Re: The Mysterious Collapse of World Trade Center 7: Why the
Posted: Fri Jul 13, 2018 2:14 am
Part 2 of 2
The Simulated versus the Real Roofline
NIST's explanation of the collapse of WTC 7, as we have seen, is based on its computer simulations of various occurrences: the initiation and spread of the fires, the resulting steel temperatures, the thermal expansion of steel beams, the failure of the girder connecting Columns 44 and 79, the failure of Column 79, and the failure of all the other columns. For most of these events, we have no visual information with which to confirm or disconfirm the simulations. With regard to a few matters, however, we do have visual (photographic and video) evidence against which to test NIST's simulations. For NIST's theory to have any plausibility, there must be a close correspondence between its simulations and all such empirical information.
One matter for which we have visual evidence is the initiation and spread of the fires. NIST's simulations, as we saw in Chapters 8 and 9, do not fare well when matched against some of this information, such as the fact that the 12th floor fire had burned out by 4:45 PM.
Another matter for which we have visual information is the appearance of the building in the first few seconds of its descent. There are videos, taken from more than one location, which can be closely studied. For NIST's analysis of the collapse of WTC 7 to be credible, therefore, NIST's simulation, on which its analysis is based, must closely correspond to what can be seen on these videos. NIST claims that it does, or at least that it corresponds "reasonably well" -- well enough to confirm the accuracy of the simulations. But this is not true.
Three features of the collapse, as revealed by these videos, especially stand out. One is the fact that, before the building as a whole began to collapse, the penthouse on the east side descended below the roofline. A second prominent feature was the development of a "kink" in the roofline of the north face. A third such feature is that, aside from that kink, the roofline remained virtually straight, as the building came down symmetrically.
With regard to the first of these features, NIST appears quite pleased with the results of its simulation, saying that "the calculated and observed times for the descent of the east penthouse below the roofline were quite similar." [47]
But as NIST prepares to discuss the second and third features -- the kink and the descent of the building -- it seeks to lower expectations, saying:
Then, with regard to the kink and the building's "subsequent movement," NIST writes:
In spite of this caveat, NIST concludes on an upbeat note, saying in a section headed "Accuracy Analysis":
Greening has expressed strong disagreement with NIST's self-evaluation here. After arguing that NIST's estimations of the available combustible materials and hence its simulated steel temperatures were unrealistic, he wrote:
Focusing on images showing what happened to the core of WTC 7 after the east penthouse collapsed, [52] according to NIST's simulations, Greening wrote:
Greening's observations here highlight one of the fundamental problems with NIST's theory of "progressive collapse." As we saw in the first part of this book, a wealth of evidence shows that explosives were used to make WTC 7 implode. A key piece of this evidence is the fact that the building came straight down. This kind of symmetrical, straight-down collapse of a steel-framed building can occur only if all of its columns fail almost simultaneously. Getting them to do this is, indeed, at the heart of the science, or art, of engineering a controlled implosion. The explosives must be in the right places and go off in the right order.
Insofar as NIST's task was to show how the building could have come down without the aid of explosives, it had an impossible task. Being unable to mention explosives, NIST could not possibly argue that all of the columns failed simultaneously. The best it could do was to develop a theory of "progressive collapse," which it defines as "the spread of local damage, from an initiating event, from element to element, eventually resulting in the collapse of an entire structure." [54] As both the name and this definition make clear, this type of collapse -- assuming for the sake of argument that it would even be possible -- would take time, with some elements happening later than others.
NIST's impossible task was to try to show that such a collapse, although very different inside the building than a controlled implosion, could look the same from the outside. NIST's attempt to do this involves arguing that most of the collapse occurred inside, invisible to external eyes and cameras, before the exterior facade, which had become a "hollow shell," collapsed. What seemed from the outside to be the total collapse of the WTC 7 was really, NIST says, only the collapse's final phase, which began when "[t]he shell of exterior columns buckled." [55]
But does this makes sense? During NIST's technical briefing in August 2008, Mindy Kleinberg, one of the 9/11 widows, asked: "If Column 79 collapsed and then 80 and 81, all of which are on the same side, why wasn't the collapse asymmetrical?" Although Shyam Sunder gave a long, poorly constructed reply at that time, [56] NIST provided a more concise and precise response in its "Questions and Answers" document, in which it said:
This strategy on NIST's part, however, could not be completely successful. The internal progression of column failures would necessarily have had noticeable effects on the building's exterior. fu Greening pointed out, if the core columns in the eastern half of the building had collapsed first, this failure would have removed the support for the eastern exterior columns, causing the eastern facade to collapse before the rest of the building did. But the videos show no such thing.
Moreover, Greening wrote, "the problems with NIST's simulations only get worse after global collapse initiation." Following his discussion of two such problems, Greening concluded with "a final blow to the credibility of NIST's collapse simulation," which he stated thus:
Why was this a fatal problem? Because, Greening explained:
[I]f NIST's collapse simulations are supposed to accurately reflect what happened to Building 7 on 9/11, one is compelled to ask: [i]Why did WTC 7 undergo a strictly vertical collapse, with the roofline remaining essentially horizontal throughout the first 5 seconds of its downward motion, when NIST's simulations show the eastern side of the building starting to collapse 4 seconds before the western side? [59][/quote]
Having raised this question in comments on NIST's Draft Report, which were posted by NIST on its website, Greening later submitted a "revised and extended version" of his critique, which NIST did not post. In this revised critique, Greening, after pointing out that the available videos "present an unobstructed view of at least the upper third of Building 7 and permit the collapse to be followed for 4-5 seconds," wrote:
By contrast, he noted, three of NIST's computer-generated images "show very extensive buckling of the exterior columns over much of the building a few seconds into the collapse." Greening then pointed out that two of these images "use lateral and vertical displacement contours that span 2 meters, a level of building distortion that should have been visible in the WTC 7 collapse videos, but was in fact not seen." [61] Two other images, Greening added, "show a localized cave-in of the top ten floors of WTC 7 at its northeast corner about the time of global collapse initiation -- another behavior of Building 7 that was never observed." [62] Having pointed out these glaring discrepancies, Greening concluded:
Greening was not the only one to complain to NIST about this lack of correspondence. Philip Tompkins wrote:
However, in spite of the obvious truth of these statements by Greening and Tompkins, made in criticism of NIST's Draft Report, those same images are reprinted in its Final Report, along with NIST's "astounding" claim that the simulations of the collapse, on which these images were based, "matched the observed behavior reasonably well." NIST perhaps understood the phrase "reasonably well" broadly enough that it could encompass "hardly at all."
Be that as it may, the fact that the simulated collapse of WTC 7 looks nothing like the actual collapse provides additional reason to conclude that NIST's explanation of that collapse is false.
Did WTC 7 Enter into Free Fall?
One of the most common arguments for the controlled demolition of WTC 7 has been based on the observation that its downward acceleration approximated that of a free-falling object. This could have happened, critics of the official account have pointed out, only if explosives of some sort had removed all of the building's structural columns. Otherwise, even if the upper part of the building had started to come down, the lower part would have stopped or at least slowed down its descent.
NIST's Draft for Public Comment:
In its Draft for Public Comment, which was issued on August 21, 2008, NIST countered this argument by claiming that the time that it took WTC 7 to collapse shows that it was not falling freely. NIST wrote:
NIST repeated this claim in a Q & A document ("Questions and Answers about the NIST WTC 7 Investigation"), which was issued the same day as the Draft Report. One of the questions was:
NIST gave the following answer (in a document that has since been removed from its website):
To say "the actual collapse time exceeded free fall time by 40 percent" was to say that the building's acceleration was only 51 percent of that of gravity. [67] Even that would have been an incredibly fast descent in a fire-induced collapse (if such were possible). But by saying that the building's acceleration was "only" 51 percent of that of a freefalling object, NIST was at least able to contradict the widespread claim that it had come down in free fall.
In his technical briefing on August 26, 2008, NIST's lead investigator, Shyam Sunder, explained why WTC 7 could not have come down in free fall:
Sunder thereby summarized the two main reasons -- even if he did not clearly distinguish between them -- why NIST could not endorse the idea that WTC 7 had come down in free fall. (1) The upper floors could not have come down in free fall, because that could have happened only if nothing of the lower floors had remained to provide structural resistance. And (2) the collapse could not have been "instantaneous," meaning that all of the supporting columns had failed simultaneously, because NIST espoused a theory of "progressive collapse," in which the failures occurred sequentially over a period of time.
David Chandler's Response to NIST's Draft Report:
Sunder's statement at the technical briefing, quoted above, was made in response to the following question from high-school physics teacher David Chandler:
Chandler's question was based on an analysis that he had presented in a video, which he had made available on the internet. In this video, Chandler first explained how he measured the downward acceleration. He then pointed out that "for about two and a half seconds ... , the acceleration of the building is indistinguishable from freefall." [70] Finally, explaining the significance of this fact, he said:
In other words, the fact that the building was in free fall for over two seconds means that zero resistance, which Sunder had tried to rule out, is exactly what there had been. How, then, had NIST claimed that the building had not been in free fall?
NIST did this, Chandler explained, by arbitrarily choosing a starting time that was earlier than the time of the actual beginning of the collapse, and then by "computing only the average acceleration between that point and the disappearance of the roofline." By alleging that the collapse began at a time when the building, in fact, had still been motionless, NIST was able to claim that it took 5.4 seconds for the top 18 floors to collapse. By then computing merely the average acceleration -- thereby ignoring the fact that the building had been in free fall for over two seconds -- NIST could claim that the collapse took 40 percent longer than would a free-falling object.
Pointing out that "[t]his is high school physics we're talking about," Chandler concluded that NIST's approach constituted "either gross incompetence or an attempt to obfuscate the issue." Indicating which of those options he endorsed, he added: "[T]he guys at NIST are not incompetent." [72]
Next, explaining why the authors of NIST's WTC 7 report had tried to obfuscate the issue, he said:
In other words, for NIST to admit that the building entered free fall, even for two seconds, would be for it to admit, implicitly, that the building had been intentionally demolished through the use of explosives of some sort.
Finally, evaluating NIST's WTC 7 report in light of this fact, Chandler concluded: "[W]e have received not a report from an independent scientific investigation, but a cover-up by a government agency." [74]
After producing his video and releasing it on the internet on September 4, 2008, Chandler next confronted NIST directly, summarizing his findings in a "Comment" about its Draft for Public Comment, submitted September 13. Stating that his measurement "shows a period of approximately 2.5 seconds, with sudden onset, during which the acceleration was indistinguishable from free fall," Chandler pointed out that the explanation he had provided in his video could easily be repeated "by anyone with a background in elementary physics." Finally, stating that Sunder's answer to his (Chandler's) question at the technical briefing constituted an acknowledgment "that the NIST model is at variance with the observable fact that free fall actually occurred," Chandler concluded: "Acknowledgment of and accounting for an extended period of free fall in the collapse of WTC 7 must be a priority if the NIST is to be taken seriously." [75]
In its Final Report, issued in November 2008, NIST does, amazingly enough, acknowledge a period of free fall. But it does not account for it.
NIST's Final Report on WTC 7:
In its Final Report, NIST still uses the early start time, thereby claiming that the upper 18 floors took 5.4 seconds to collapse. It also continues to use the average descent rate. NIST can thereby continue saying that the building took 40 percent longer than free-fall time to collapse. All of these elements are contained in the following summary statement:
Within this unchanged framework, however, NIST goes beyond its former approach by dividing this 5.4-second period into three stages, in which it acknowledges the point on which Chandler had been insisting. After repeating the claim that the descent time of the upper 18 stories "was 40 percent greater than the computed free fall time," NIST says on page 607 of the long version of its Final Report:
Although this is stated matter-of-factly, as if nothing extraordinary were being said, NIST's three-phase analysis includes, in Chandler's words, "a whopping 2.25 seconds of absolute free fall." [78]
NIST has thereby contradicted its claim, made in its Q & A document of August 2008, that "WTC 7 did not enter free fall." It now acknowledges that WTC 7 not only entered free fall but remained in it for 2.25 seconds -- which means that, for over two seconds, the lower floors of the building were offering zero resistance.
NIST also admits this point in an updated version of its Q & A document, issued in December 2008. This document's description of the three stages of collapse says: "During Stage 2, the north face descended essentially in free fall, indicating negligible support from the structure below." [79] This is, of course, exactly what Sunder in his technical briefing of August 2008 had said could not have occurred. NIST has clearly reversed itself -- a point that Chandler emphasized with the title of his next video: "WTC 7: NIST Finally Admits Freefall."
NIST does not, to be sure, admit that the 2.25 seconds of zero resistance implies that explosives had been used to remove all the steel and concrete that would have offered resistance. But neither has NIST continued to insist that its non-demolition collapse analysis, now that it explicitly includes a free-fall stage, is consistent with physical principles.
In its Draft for Public Comment, as we saw earlier, NIST had made that claim, saying:
This claim was reiterated in the next paragraph, which said:
In the list of "Principal Findings" at the end of the Draft Report, NIST again made this claim, saying:
In NIST's Final Report, however, this claim, so prominent in the Draft for Public Comment, is missing. The claim that NIST's analysis is consistent with physical principles is replaced by NIST's new three-stage analysis. For example, the just-quoted statement from the list of "Principal Findings" has been modified to read:
No claim that this three-stage analysis is "consistent with physical principles" is made here or anywhere else in NIST's Final Report on WTC7.
NIST's Final Report does include a "consistent with" statement, but this statement says nothing about physical principles. Instead, after giving its three-stage analysis, NIST says: "The three stages of collapse progression described above are consistent with the results of the global collapse analyses discussed earlier in this chapter." [83] What NIST asserts, in other words, is that its three-stage analysis on this page is consistent with its three-stage analyses on earlier pages! This tautological statement is a far cry from NIST's earlier claim that its collapse analysis was consistent with physical principles.
In omitting every instance of this earlier claim, NIST has implicitly conceded that its collapse analysis is not consistent with physical principles. NIST tries, nevertheless, to disguise this fact by continuing to claim that WTC 7's descent time was 40 percent longer than free fall. In his new video, "WTC7: NIST Finally Admits Freefall," Chandler has explained, more fully than he had before, why this claim is fraudulent.
Chandler on NIST's "40 Percent Greater than Free Fall" Claim:
Before looking at Chandler's critique of NIST's claim that the descent of the top 18 floors took 5.4 seconds, it will be helpful to look at the summary of NIST's three-stage analysis of this 5.4-second period, which is provided in its updated Q & A document:
Chandler fully agrees with Stages 2 and 3. Stage 2 is, of course, the 2.25 seconds of free fall on which he has insisted. (Although he originally timed it at 2.5 seconds, he has not quibbled about its reduction to 2.25 seconds.) He also agrees that, after this stage of absolute free fall, the descent started to slow. As he said in his critique of NIST's Draft Report:
Chandler agrees, therefore, that the stage of absolute free fall was followed by a stage in which the acceleration decreased. He also agrees that it is important to distinguish clearly between these two stages.
Chandler's point of disagreement with NIST's three-stage analysis involves the period lasting 1.75 seconds, which NIST calls Stage 1 of the collapse. It is this so-called first stage that allows NIST to claim that the collapse of the upper 18 floors required 5.4 seconds and hence took 40 percent longer than free fall. NIST itself even points out this fact in its new Q & A document, saying that "the 40 percent longer descent time -- compared to the 3.9 second free fall time -- was due primarily to Stage 1." [86] NIST also makes this point in its Final Report, saying that the "increase in time is due primarily to Stage 1, in which column buckling was just beginning and gradual progression in displacement and velocity were observed." [87] Chandler challenged the second half of that statement, pointing out that no significant movement was observed during almost all of this so-called first stage.
Chandler demonstrated this fact by slowing down the video footage, so that the collapse of the upper 18 floors could be analyzed frame by frame. He used a video in which there are 30 frames per second, so that it takes 162 frames to show the 5.4 seconds that, according to NIST, it took WTC 7's roofline to descend to the level where the 29th floor had been (after which the building disappeared from view behind other buildings).
Although NIST said that WTC 7's collapse started exactly 5.4 seconds before the roofline reached that level, Chandler pointed out that there is not "the slightest hint of any collapse until Frame 40." [88] That frame, moreover, merely shows a tiny motion in the corner of the west penthouse, after which the penthouse begins to collapse into the roof. WTC 7's roofline itself remains motionless until about Frame 46. "Even then," Chandler pointed out, "there isn't any progressive, ongoing movement of the roofline until about Frame 60," [89] which shows the building 1.5 seconds later than the time at which NIST claimed the collapse had begun.
So why did NIST claim that the collapse began 1.5 seconds prior to the time at which this ongoing movement of the roofline occurred? Chandler said:
The purpose, in other words, was to obscure the fact that WTC 7, after being motionless, suddenly began to come down in free fall.
Did Chandler's use of the word "fabrication" mean that he was accusing NIST of scientific fraud? Yes. He even used the term "dry labbing," [91] which, as mentioned in Chapter 2, is often used as a synonym for fabrication.
Chandler on the Significance of WTC 7's Free-Fall Descent:
After exposing the fraudulent nature of NIST's claim that the descent of the upper 18 floors took 40 percen t longer than free fall, Chandler discussed the significance of NIST's belated admission that WTC 7 came down in free fall for over two seconds. Explaining the basic physical principles involved, Chandler said:
However, Chandler continued, the [i]way in which WTC 7 came down provides even stronger evidence of its explosive demolition:
Still further evidence is provided, Chandler said, by another fact about WTC 7's descent:
Having made that point -- which is surely the clearest proof that explosives of some sort were used to remove the columns -- Chandler emphasized the importance of recognizing the deceptiveness of NIST's three-stage analysis:
Finally, pointing out the contradiction between NIST's collapse model and the empirical fact that WTC 7 was in free fall for over two seconds -- which NIST has reluctantly admitted -- Chandler concluded:
In other words, by admitting "a free-fall component," NIST has ended up with a self-contradictory position. On the one hand, its Final Report offers the same theory of WTC 7's collapse that was contained in its Draft Report, which was a theory of progressive collapse, in which the building's supports failed sequentially. On the other hand, NIST's Final Report concedes that the building came down part of the time in free fall, which means that all of the supports had to have failed simultaneously.
Given this contradiction at the very heart of the final version of NIST's theory, Shyam Sunder should be asked by the press whether he still stands by his confident assertion at the August 2008 press briefing that, thanks to NIST's analysis, "the reason for the collapse of World Trade Center 7 is no longer a mystery." [97] Far from solving the mystery of WTC 7's collapse, NIST has -- by continuing to provide a non-demolition theory of this collapse while admitting that it involved over two seconds of complete free fall -- built an absolute mystery into the official explanation.
Sunder also needs to be asked whether he still stands by his statement, made on that same occasion, that "science is really behind what we have said." [98] If he still believes this, why are all of NIST's previous claims that its analysis is "consistent with physical principles" missing in the final version of its report?
These claims had to be removed, of course, because Sunder and his fellow scientists at NIST know that the 2.25-second period of free fall they have admitted is not consistent with physical principles. Outdoing the cartoon mentioned in Chapter 2, these NIST scientists presented 606 pages of descriptions, testimonies, photographs, graphs, analyses, mathematical formulae, and explanations, after which they in effect said on page 607: "Then a miracle happens."
The Compact Debris Pile
Having shown that NIST's theory of progressive collapse cannot do justice to the actual collapse of WTC 7, as observed on videos, I will conclude this chapter by showing that this theory also cannot explain the result: a very compact debris pile, no more than two stories high, that was almost entirely within the building's footprint. (Photos showing this very tidy pile of rubble, situated cleanly between the neighboring buildings, are available on the internet. [99])
Phillip Tompkins, whose comment to NIST about its picture of the collapse was quoted above, also drew attention to this problem, writing: "I do not see how [NIST] explains the contents of the pile at the end of the collapse. Where and in what condition were all the long core columns?" [100]
I myself had raised this problem -- about all of the columns, not only the core columns -- in an earlier book. Having quoted the statement by New York Times writer James Glanz that, if the collapse of WTC 7 had not been overshadowed by that of the Twin Towers, it would have been "a mystery that ... would probably have captured the attention of the city and the world," [101] I wrote:
My statement contained two errors: First, although there were indeed 24 interior columns, only 21 of them were core columns (the other three -- Columns 79, 80, and 81 -- were in the eastern region of the building); second, there were 58 perimeter (exterior) columns, not 57, hence a total of 82 columns. [103] Correcting these two errors does not, however, affect the problem raised by my statement: Given the existence of all those columns, how could virtually all of the debris from the collapse have ended up in the building's footprint?
Here is the problem: WTC 7 was 610 feet high, so each column was 610 feet long. According to NIST's theory, the columns all buckled between the 7th and 14th floors, [104] after which "the entire building above the buckled-column region moved downward as a single unit." [105] Even if all of the columns buckled exactly at the 14th floor, the unbroken sections from the upper 33 floors would have been 429 feet long (each floor was 13 feet high).
Could these 429-foot-long columns have all come down into WTC 7's footprint? The building, which had a trapezoidal shape, was 247 feet long on the south side, 329 feet long on the north side, and about 150 feet on the east and west sides. [106] So even if all the columns had been placed in the middle of the footprint with their ends pointing east and west, they would not have fit within the footprint.
The columns, moreover, would not have come down so neatly. Many would have fallen outside the footprint in various directions, blocking the streets and destroying numerous nearby buildings, especially the Federal Building and the New York Telephone Building, which were very close to WTC 7. [107] That, however, did not happen -- which means that the columns must have been broken into smaller segments before they came down.
The compact pile of debris that resulted from the collapse of WTC 7 is what would be expected from the kind of controlled demolition known as "implosion," in which explosives are used to cut the steel columns in the right places and in the right order to make the building fold in on itself. During an interview in 1996, Stacey Loizeaux -- daughter of Mark Loizeaux, the president of Controlled Demolition, Inc. -- explained how it is done:
There is, accordingly, an obvious explanation for the fact that WTC 7 collapsed into a relatively small pile of debris, with "small, manageable pieces" of steel. This is the same explanation that would account for the melted and sulfidized steel, the thermite residue in the dust, the reports of explosions in the building, and the rapid, straight-down collapse of the building, with over two seconds of absolute free fall. This is, in other words, the explanation that scientists guided by Occam's razor would have chosen.
NIST, however, refused to entertain this obvious explanation. As a result, it could not explain why the area surrounding the site of WTC 7 was not littered with 82 columns that were each at least 429 feet long. It simply ignores the problem, evidently hoping that no one -- at least no one who matters, such as the press or the next administration's Department of Justice -- would notice.
* * *
Every aspect of NIST's theory of a fire-induced global collapse of WTC 7, we have seen, depends on implausible claims and outright fabrications. Its theory of weakened floor beams depends on implausible steel temperatures, which in turn depend on implausible fire temperatures and durations. Its theory of thermally induced girder failure depends on two cases of fraud: denying the existence of shear studs and fabricating a "differential thermal expansion" in its computer simulation by heating the steel beams but not the floor slabs. Its theory of how thermally expanded beams wreaked havoc presupposes an implausible amount of elongation.
And yet, even with all of these fabrications and implausibilities, NIST ends up with a theory that cannot explain several obvious features of WTC 7's collapse: that the building's roofline remained essentially horizontal, that its upper floors came down in free fall for over two seconds, and that its debris ended up in a tidy pile, with most of it contained within the building's footprint.
The Simulated versus the Real Roofline
NIST's explanation of the collapse of WTC 7, as we have seen, is based on its computer simulations of various occurrences: the initiation and spread of the fires, the resulting steel temperatures, the thermal expansion of steel beams, the failure of the girder connecting Columns 44 and 79, the failure of Column 79, and the failure of all the other columns. For most of these events, we have no visual information with which to confirm or disconfirm the simulations. With regard to a few matters, however, we do have visual (photographic and video) evidence against which to test NIST's simulations. For NIST's theory to have any plausibility, there must be a close correspondence between its simulations and all such empirical information.
One matter for which we have visual evidence is the initiation and spread of the fires. NIST's simulations, as we saw in Chapters 8 and 9, do not fare well when matched against some of this information, such as the fact that the 12th floor fire had burned out by 4:45 PM.
Another matter for which we have visual information is the appearance of the building in the first few seconds of its descent. There are videos, taken from more than one location, which can be closely studied. For NIST's analysis of the collapse of WTC 7 to be credible, therefore, NIST's simulation, on which its analysis is based, must closely correspond to what can be seen on these videos. NIST claims that it does, or at least that it corresponds "reasonably well" -- well enough to confirm the accuracy of the simulations. But this is not true.
Three features of the collapse, as revealed by these videos, especially stand out. One is the fact that, before the building as a whole began to collapse, the penthouse on the east side descended below the roofline. A second prominent feature was the development of a "kink" in the roofline of the north face. A third such feature is that, aside from that kink, the roofline remained virtually straight, as the building came down symmetrically.
With regard to the first of these features, NIST appears quite pleased with the results of its simulation, saying that "the calculated and observed times for the descent of the east penthouse below the roofline were quite similar." [47]
But as NIST prepares to discuss the second and third features -- the kink and the descent of the building -- it seeks to lower expectations, saying:
Once simulation of the global collapse of WTC 7 was underway, there was a great increase in the uncertainty in the progression of the collapse sequence, due to the random nature of the interaction .... [T]he details of the progression of the horizontal failure and final global collapse were increasingly less precise. [48]
Then, with regard to the kink and the building's "subsequent movement," NIST writes:
There was another observable feature that occurred after the global collapse was underway. After the exterior facade began to fall downward ... , the north face developed a line or "kink" near the end of the core at Column 76,. .. The kink ... occurred 2 s[econds] to 3 s[seconds] after the exterior facade had begun to move downward, as a result of the global collapse. The simulations do show the formation of the kink, but any subsequent movement of the building is beyond the reliability of the physics in the model. [49]
In spite of this caveat, NIST concludes on an upbeat note, saying in a section headed "Accuracy Analysis":
Given the complexity of the modeled behavior, the global collapse analyses matched the observed behavior reasonably well. ... The global collapse analysis confirmed the leading collapse hypothesis, which was based on the available evidence. [50]
Greening has expressed strong disagreement with NIST's self-evaluation here. After arguing that NIST's estimations of the available combustible materials and hence its simulated steel temperatures were unrealistic, he wrote:
However, assume for a moment that collapse initiation in WTC 7 did in fact occur as NIST states: by a thermally induced buckling failure of Column 79 on Floors 12/13. It would then be appropriate to ask: Is the collapse propagation mechanism proposed by NIST consistent with the observed collapse of WTC 7? If the answer to this question is "Yes," it would add credibility to NIST's account of what happened to Building 7 on 9/11 even if an inappropriate fuel loading was used to arrive at this conclusion. However, I would suggest that NIST's account of the last 1/2 minute of the life of WTC 7 ... is... at odds with what was observed in the collapse videos of WTC 7. [51]
Focusing on images showing what happened to the core of WTC 7 after the east penthouse collapsed, [52] according to NIST's simulations, Greening wrote:
What is most significant about these images is that around the time of global collapse initiation NIST's simulation shows that the eastern half of the core had completely collapsed while the western half of the core remained standing and relatively undamaged. This is quite remarkable since videos of the collapse of WTC 7 show that up to and well beyond the moment that the roofline of WTC 7 exhibited its first downward movement, the exterior of the building revealed absolutely no signs of NIST's proposed partial collapse of the core even though the core was connected to the exterior walls of Building 7 by dozens of horizontal beams on every floor.
NIST's proposed collapse of the eastern half of the core would have completely removed the lateral restraints normally acting on the eastern exterior columns of WTC 7. Indeed, NIST assert[s] that in the moments before global collapse initiation, "the exterior facade on the east quarter of the building was just a hollow shell." This would have caused the eastern facade to buckle well before global collapse ensued. This buckling would have been visible as a bowing of the northeast corner of the building. Needless to say, such pre-collapse buckling or bowing of WTC 7 was not observed. [53]
Greening's observations here highlight one of the fundamental problems with NIST's theory of "progressive collapse." As we saw in the first part of this book, a wealth of evidence shows that explosives were used to make WTC 7 implode. A key piece of this evidence is the fact that the building came straight down. This kind of symmetrical, straight-down collapse of a steel-framed building can occur only if all of its columns fail almost simultaneously. Getting them to do this is, indeed, at the heart of the science, or art, of engineering a controlled implosion. The explosives must be in the right places and go off in the right order.
Insofar as NIST's task was to show how the building could have come down without the aid of explosives, it had an impossible task. Being unable to mention explosives, NIST could not possibly argue that all of the columns failed simultaneously. The best it could do was to develop a theory of "progressive collapse," which it defines as "the spread of local damage, from an initiating event, from element to element, eventually resulting in the collapse of an entire structure." [54] As both the name and this definition make clear, this type of collapse -- assuming for the sake of argument that it would even be possible -- would take time, with some elements happening later than others.
NIST's impossible task was to try to show that such a collapse, although very different inside the building than a controlled implosion, could look the same from the outside. NIST's attempt to do this involves arguing that most of the collapse occurred inside, invisible to external eyes and cameras, before the exterior facade, which had become a "hollow shell," collapsed. What seemed from the outside to be the total collapse of the WTC 7 was really, NIST says, only the collapse's final phase, which began when "[t]he shell of exterior columns buckled." [55]
But does this makes sense? During NIST's technical briefing in August 2008, Mindy Kleinberg, one of the 9/11 widows, asked: "If Column 79 collapsed and then 80 and 81, all of which are on the same side, why wasn't the collapse asymmetrical?" Although Shyam Sunder gave a long, poorly constructed reply at that time, [56] NIST provided a more concise and precise response in its "Questions and Answers" document, in which it said:
WTC 7's collapse, viewed from the exterior (most videos were taken from the north), did appear to fall almost uniformly as a single unit. This occurred because the interior failures that took place did not cause the exterior framing to fail until the final stages of the building collapse. The interior floor framing and columns collapsed downward and pulled away from the exterior frame. There were clues that internal damage was taking place, prior to the downward movement of the exterior frame, such as when the east penthouse fell downward into the building and windows broke out on the north face at the ends of the building core. The symmetric appearance of the downward fall of the WTC 7 was primarily due to the greater stiffness and strength of its exterior frame relative to the interior framing. [57]
This strategy on NIST's part, however, could not be completely successful. The internal progression of column failures would necessarily have had noticeable effects on the building's exterior. fu Greening pointed out, if the core columns in the eastern half of the building had collapsed first, this failure would have removed the support for the eastern exterior columns, causing the eastern facade to collapse before the rest of the building did. But the videos show no such thing.
Moreover, Greening wrote, "the problems with NIST's simulations only get worse after global collapse initiation." Following his discussion of two such problems, Greening concluded with "a final blow to the credibility of NIST's collapse simulation," which he stated thus:
[NIST's computer-based images] reveal a collapsing core with its eastern side a full eight stories ... below its western side. This would indicate a roofline collapse that started at the eastern end of Building 7 and progressed over a period of about 4 seconds to the western end. [58]
Why was this a fatal problem? Because, Greening explained:
[I]f NIST's collapse simulations are supposed to accurately reflect what happened to Building 7 on 9/11, one is compelled to ask: [i]Why did WTC 7 undergo a strictly vertical collapse, with the roofline remaining essentially horizontal throughout the first 5 seconds of its downward motion, when NIST's simulations show the eastern side of the building starting to collapse 4 seconds before the western side? [59][/quote]
Having raised this question in comments on NIST's Draft Report, which were posted by NIST on its website, Greening later submitted a "revised and extended version" of his critique, which NIST did not post. In this revised critique, Greening, after pointing out that the available videos "present an unobstructed view of at least the upper third of Building 7 and permit the collapse to be followed for 4-5 seconds," wrote:
The videos show the upper section of WTC 7 descending very smoothly as an intact structure, with the roofline remaining essentially horizontal until it passes behind buildings in the foreground. The only significant distortion of the boxed-shaped Building 7 that is noticeable after the facade begins its downward motion is the formation of a kink on the eastern side of the north face. [60]
By contrast, he noted, three of NIST's computer-generated images "show very extensive buckling of the exterior columns over much of the building a few seconds into the collapse." Greening then pointed out that two of these images "use lateral and vertical displacement contours that span 2 meters, a level of building distortion that should have been visible in the WTC 7 collapse videos, but was in fact not seen." [61] Two other images, Greening added, "show a localized cave-in of the top ten floors of WTC 7 at its northeast corner about the time of global collapse initiation -- another behavior of Building 7 that was never observed." [62] Having pointed out these glaring discrepancies, Greening concluded:
It is simply astounding that, although NIST's computer generated images of a crumpled and severely distorted Building 7 look nothing like the video images of the real thing, NIST nevertheless concludes: ''the global collapse analyses matched the observed behavior reasonably well." [63]
Greening was not the only one to complain to NIST about this lack of correspondence. Philip Tompkins wrote:
I do not see how the pictured object in Figure 12- [70] at all resembles the actual collapse as shown in the videos. In the actual collapse the top of the building is not all crumpled as in Figure 12-[70]. [64]
However, in spite of the obvious truth of these statements by Greening and Tompkins, made in criticism of NIST's Draft Report, those same images are reprinted in its Final Report, along with NIST's "astounding" claim that the simulations of the collapse, on which these images were based, "matched the observed behavior reasonably well." NIST perhaps understood the phrase "reasonably well" broadly enough that it could encompass "hardly at all."
Be that as it may, the fact that the simulated collapse of WTC 7 looks nothing like the actual collapse provides additional reason to conclude that NIST's explanation of that collapse is false.
Did WTC 7 Enter into Free Fall?
One of the most common arguments for the controlled demolition of WTC 7 has been based on the observation that its downward acceleration approximated that of a free-falling object. This could have happened, critics of the official account have pointed out, only if explosives of some sort had removed all of the building's structural columns. Otherwise, even if the upper part of the building had started to come down, the lower part would have stopped or at least slowed down its descent.
NIST's Draft for Public Comment:
In its Draft for Public Comment, which was issued on August 21, 2008, NIST countered this argument by claiming that the time that it took WTC 7 to collapse shows that it was not falling freely. NIST wrote:
The time the roofline took to fall 18 stories was 5.4 s[econds].... Thus, the actual time for the upper 18 floors of the north face to collapse, based on video evidence, was approximately 40 percent longer than the computed free fall time and was consistent with physical principles. [65]
NIST repeated this claim in a Q & A document ("Questions and Answers about the NIST WTC 7 Investigation"), which was issued the same day as the Draft Report. One of the questions was:
In videos, it appears that WTC 7 is descending in free fall, something that would not occur in the structural collapse that you describe. How can you ignore basic laws of physics?
NIST gave the following answer (in a document that has since been removed from its website):
WTC 7 did not enter free fall. According to NIST analysis of WTC 7 video, the building collapsed 18 stories in 5.3 seconds [sic: NIST usually said 5.4 seconds]. If the building exhibited free fall, this process would have taken just 3.9 seconds. The actual collapse time exceeded the free fall time by 40 percent. [66]
To say "the actual collapse time exceeded free fall time by 40 percent" was to say that the building's acceleration was only 51 percent of that of gravity. [67] Even that would have been an incredibly fast descent in a fire-induced collapse (if such were possible). But by saying that the building's acceleration was "only" 51 percent of that of a freefalling object, NIST was at least able to contradict the widespread claim that it had come down in free fall.
In his technical briefing on August 26, 2008, NIST's lead investigator, Shyam Sunder, explained why WTC 7 could not have come down in free fall:
[A] free fall time would be an object that has no structural components below it. ... What the ... collapse analysis shows, is that same time [sic] that it took for the structural model to come down from the roof line all the way -- for those 17 floors to disappear -- is 5.4 seconds. It's about 1.5 seconds, or roughly 40 percent, more time for that free fall to happen [sic]. And that is not at all unusual, because there was structural resistance that was provided in this particular case. And you had a sequence of structural failures that had to take place. Everything was not instantaneous. [68]
Sunder thereby summarized the two main reasons -- even if he did not clearly distinguish between them -- why NIST could not endorse the idea that WTC 7 had come down in free fall. (1) The upper floors could not have come down in free fall, because that could have happened only if nothing of the lower floors had remained to provide structural resistance. And (2) the collapse could not have been "instantaneous," meaning that all of the supporting columns had failed simultaneously, because NIST espoused a theory of "progressive collapse," in which the failures occurred sequentially over a period of time.
David Chandler's Response to NIST's Draft Report:
Sunder's statement at the technical briefing, quoted above, was made in response to the following question from high-school physics teacher David Chandler:
Any number of competent measurements using a variety of methods indicate the northwest corner of WTC 7 fell with an acceleration within a few percent of the acceleration of gravity. Yet your report contradicts this, claiming 40 percent slower than free fall.... How can such a publicly visible, easily measurable quantity be set aside? [69]
Chandler's question was based on an analysis that he had presented in a video, which he had made available on the internet. In this video, Chandler first explained how he measured the downward acceleration. He then pointed out that "for about two and a half seconds ... , the acceleration of the building is indistinguishable from freefall." [70] Finally, explaining the significance of this fact, he said:
Free fall can only be achieved if there is zero resistance to the motion. In other words, the gravitational potential energy of the building is not available to crush or deform anything. During free fall, all of the gravitational potential energy of the building is being converted into kinetic energy, and nothing else. Any breaking, bending, crushing, or pulverizing of the building components is occurring without the assistance of the free-falling portion of the building. Any force the top portion of the building might exert on the lower portion would be reflected in a reaction force that would produce an observable slowing of the rate of fall. [71]
In other words, the fact that the building was in free fall for over two seconds means that zero resistance, which Sunder had tried to rule out, is exactly what there had been. How, then, had NIST claimed that the building had not been in free fall?
NIST did this, Chandler explained, by arbitrarily choosing a starting time that was earlier than the time of the actual beginning of the collapse, and then by "computing only the average acceleration between that point and the disappearance of the roofline." By alleging that the collapse began at a time when the building, in fact, had still been motionless, NIST was able to claim that it took 5.4 seconds for the top 18 floors to collapse. By then computing merely the average acceleration -- thereby ignoring the fact that the building had been in free fall for over two seconds -- NIST could claim that the collapse took 40 percent longer than would a free-falling object.
Pointing out that "[t]his is high school physics we're talking about," Chandler concluded that NIST's approach constituted "either gross incompetence or an attempt to obfuscate the issue." Indicating which of those options he endorsed, he added: "[T]he guys at NIST are not incompetent." [72]
Next, explaining why the authors of NIST's WTC 7 report had tried to obfuscate the issue, he said:
The rate of fall of the building is an embarrassment to the official theory.. .. Buildings cannot fall at free fall through themselves, because even a weakened building requires energy to break up the pieces, crush the concrete, and push things around. When a falling building pushes things, the fall is not free, the "things" push back, and the reaction forces will measurably slow the descent of the building. This is why one would reasonably expect crumbling structures to come down in a tumbling, halting, irregular manner. In short, the evidence is clear: we are witnessing not the collapse of a building, but its demolition. [73]
In other words, for NIST to admit that the building entered free fall, even for two seconds, would be for it to admit, implicitly, that the building had been intentionally demolished through the use of explosives of some sort.
Finally, evaluating NIST's WTC 7 report in light of this fact, Chandler concluded: "[W]e have received not a report from an independent scientific investigation, but a cover-up by a government agency." [74]
After producing his video and releasing it on the internet on September 4, 2008, Chandler next confronted NIST directly, summarizing his findings in a "Comment" about its Draft for Public Comment, submitted September 13. Stating that his measurement "shows a period of approximately 2.5 seconds, with sudden onset, during which the acceleration was indistinguishable from free fall," Chandler pointed out that the explanation he had provided in his video could easily be repeated "by anyone with a background in elementary physics." Finally, stating that Sunder's answer to his (Chandler's) question at the technical briefing constituted an acknowledgment "that the NIST model is at variance with the observable fact that free fall actually occurred," Chandler concluded: "Acknowledgment of and accounting for an extended period of free fall in the collapse of WTC 7 must be a priority if the NIST is to be taken seriously." [75]
In its Final Report, issued in November 2008, NIST does, amazingly enough, acknowledge a period of free fall. But it does not account for it.
NIST's Final Report on WTC 7:
In its Final Report, NIST still uses the early start time, thereby claiming that the upper 18 floors took 5.4 seconds to collapse. It also continues to use the average descent rate. NIST can thereby continue saying that the building took 40 percent longer than free-fall time to collapse. All of these elements are contained in the following summary statement:
The time that the roofline took to fall 18 stories... was approximately 5.4 s[econds]. The theoretical time for free fall was approximately 3.9 s[econds]. Thus, the average time for the upper 18 stories to collapse, based on video evidence,... was approximately 40 percent longer than the computed free fall time. [76]
Within this unchanged framework, however, NIST goes beyond its former approach by dividing this 5.4-second period into three stages, in which it acknowledges the point on which Chandler had been insisting. After repeating the claim that the descent time of the upper 18 stories "was 40 percent greater than the computed free fall time," NIST says on page 607 of the long version of its Final Report:
A more detailed analysis of the descent of the north face found three stages: (1) a slow descent with acceleration less than that of gravity that corresponded to the buckling of the exterior columns at the lower floors, (2) a freefall descent over approximately eight stories at gravitational acceleration for approximately 2.25 s[econds], and (3) a decreasing acceleration as the north face encountered resistance from the structure below. [77]
Although this is stated matter-of-factly, as if nothing extraordinary were being said, NIST's three-phase analysis includes, in Chandler's words, "a whopping 2.25 seconds of absolute free fall." [78]
NIST has thereby contradicted its claim, made in its Q & A document of August 2008, that "WTC 7 did not enter free fall." It now acknowledges that WTC 7 not only entered free fall but remained in it for 2.25 seconds -- which means that, for over two seconds, the lower floors of the building were offering zero resistance.
NIST also admits this point in an updated version of its Q & A document, issued in December 2008. This document's description of the three stages of collapse says: "During Stage 2, the north face descended essentially in free fall, indicating negligible support from the structure below." [79] This is, of course, exactly what Sunder in his technical briefing of August 2008 had said could not have occurred. NIST has clearly reversed itself -- a point that Chandler emphasized with the title of his next video: "WTC 7: NIST Finally Admits Freefall."
NIST does not, to be sure, admit that the 2.25 seconds of zero resistance implies that explosives had been used to remove all the steel and concrete that would have offered resistance. But neither has NIST continued to insist that its non-demolition collapse analysis, now that it explicitly includes a free-fall stage, is consistent with physical principles.
In its Draft for Public Comment, as we saw earlier, NIST had made that claim, saying:
[T]he actual time for the upper 18 floors of the north face to collapse ... was approximately 40 percent longer than the computed free fall time and was consistent with physical principles.
This claim was reiterated in the next paragraph, which said:
The actual collapse time of the upper 18 floors of the north face of WTC 7 ... was 40 percent greater than the computed free fall time. This was consistent with physical principles. [80]
In the list of "Principal Findings" at the end of the Draft Report, NIST again made this claim, saying:
The collapse time of the upper 18 floors of the north face of WTC 7 ... was 40 percent greater than the computed free fall time. This is consistent with physical principles. [81]
In NIST's Final Report, however, this claim, so prominent in the Draft for Public Comment, is missing. The claim that NIST's analysis is consistent with physical principles is replaced by NIST's new three-stage analysis. For example, the just-quoted statement from the list of "Principal Findings" has been modified to read:
The observed descent time of the upper 18 stories of the north face of WTC 7 ... was 40 percent greater than the computed free fall time. A more detailed analysis of the descent of the north face found three stages: (1) a slow descent with acceleration less than that of gravity that corresponded to the buckling of the exterior columns at the lower floors, (2) a freefall descent over approximately eight stories at gravitational acceleration for approximately 2.25 s[econds], and (3) a decreasing acceleration as the north face encountered resistance from the structure below. [82]
No claim that this three-stage analysis is "consistent with physical principles" is made here or anywhere else in NIST's Final Report on WTC7.
NIST's Final Report does include a "consistent with" statement, but this statement says nothing about physical principles. Instead, after giving its three-stage analysis, NIST says: "The three stages of collapse progression described above are consistent with the results of the global collapse analyses discussed earlier in this chapter." [83] What NIST asserts, in other words, is that its three-stage analysis on this page is consistent with its three-stage analyses on earlier pages! This tautological statement is a far cry from NIST's earlier claim that its collapse analysis was consistent with physical principles.
In omitting every instance of this earlier claim, NIST has implicitly conceded that its collapse analysis is not consistent with physical principles. NIST tries, nevertheless, to disguise this fact by continuing to claim that WTC 7's descent time was 40 percent longer than free fall. In his new video, "WTC7: NIST Finally Admits Freefall," Chandler has explained, more fully than he had before, why this claim is fraudulent.
Chandler on NIST's "40 Percent Greater than Free Fall" Claim:
Before looking at Chandler's critique of NIST's claim that the descent of the top 18 floors took 5.4 seconds, it will be helpful to look at the summary of NIST's three-stage analysis of this 5.4-second period, which is provided in its updated Q & A document:
-- Stage 1 (0 to 1.75 seconds): acceleration less than that of gravity (i.e., slower than free fall)
-- Stage 2 (1.75 to 4.0 seconds): gravitational acceleration (freefall)
-- Stage 3 (4.0 to 5.4 seconds): decreased acceleration, again less than that of gravity [84]
Chandler fully agrees with Stages 2 and 3. Stage 2 is, of course, the 2.25 seconds of free fall on which he has insisted. (Although he originally timed it at 2.5 seconds, he has not quibbled about its reduction to 2.25 seconds.) He also agrees that, after this stage of absolute free fall, the descent started to slow. As he said in his critique of NIST's Draft Report:
[A]bout two and a half seconds after the building drops, the acceleration ceases to be uniform. This indicates that the falling building is scarring to offer more resistance. Any measurement of the average acceleration that continues for more than the first two and a half seconds of fall will show a lower average acceleration, masking the fact that for a significant two and a half seconds the building was in literal free fall. [85]
Chandler agrees, therefore, that the stage of absolute free fall was followed by a stage in which the acceleration decreased. He also agrees that it is important to distinguish clearly between these two stages.
Chandler's point of disagreement with NIST's three-stage analysis involves the period lasting 1.75 seconds, which NIST calls Stage 1 of the collapse. It is this so-called first stage that allows NIST to claim that the collapse of the upper 18 floors required 5.4 seconds and hence took 40 percent longer than free fall. NIST itself even points out this fact in its new Q & A document, saying that "the 40 percent longer descent time -- compared to the 3.9 second free fall time -- was due primarily to Stage 1." [86] NIST also makes this point in its Final Report, saying that the "increase in time is due primarily to Stage 1, in which column buckling was just beginning and gradual progression in displacement and velocity were observed." [87] Chandler challenged the second half of that statement, pointing out that no significant movement was observed during almost all of this so-called first stage.
Chandler demonstrated this fact by slowing down the video footage, so that the collapse of the upper 18 floors could be analyzed frame by frame. He used a video in which there are 30 frames per second, so that it takes 162 frames to show the 5.4 seconds that, according to NIST, it took WTC 7's roofline to descend to the level where the 29th floor had been (after which the building disappeared from view behind other buildings).
Although NIST said that WTC 7's collapse started exactly 5.4 seconds before the roofline reached that level, Chandler pointed out that there is not "the slightest hint of any collapse until Frame 40." [88] That frame, moreover, merely shows a tiny motion in the corner of the west penthouse, after which the penthouse begins to collapse into the roof. WTC 7's roofline itself remains motionless until about Frame 46. "Even then," Chandler pointed out, "there isn't any progressive, ongoing movement of the roofline until about Frame 60," [89] which shows the building 1.5 seconds later than the time at which NIST claimed the collapse had begun.
So why did NIST claim that the collapse began 1.5 seconds prior to the time at which this ongoing movement of the roofline occurred? Chandler said:
The only rationale I can see ... is to make the measurement come out to exactly 5.4 seconds, w agree with the prediction of NIST's collapse model. ... t's pretty clear that the whole idea there's any kind of real 5.4 second collapse interval is a fiction. It's a crude fabrication, and the 3-stage collapse sequence is pseudo-science in the service of an ongoing coverup. [90]
The purpose, in other words, was to obscure the fact that WTC 7, after being motionless, suddenly began to come down in free fall.
Did Chandler's use of the word "fabrication" mean that he was accusing NIST of scientific fraud? Yes. He even used the term "dry labbing," [91] which, as mentioned in Chapter 2, is often used as a synonym for fabrication.
Chandler on the Significance of WTC 7's Free-Fall Descent:
After exposing the fraudulent nature of NIST's claim that the descent of the upper 18 floors took 40 percen t longer than free fall, Chandler discussed the significance of NIST's belated admission that WTC 7 came down in free fall for over two seconds. Explaining the basic physical principles involved, Chandler said:
Anything at an elevated height has gravitational potential energy. If it falls, and none of the energy is used for other things along the way, all of that energy is converted into kinetic energy -- the energy of motion, and we call it "free fall." If any of the energy is used for other purposes, there will be less kinetic energy, so the fall will be slower. In the case of a falling building, the only way it can go into free fall is if an external force removes the supporting structure. None of the gravitational potential energy of the building is available for this purpose, or it would slow the fall of the building. The fact of free fall by itself is strong evidence of explosive demolition. [92]
However, Chandler continued, the [i]way in which WTC 7 came down provides even stronger evidence of its explosive demolition:
What is particularly striking is the suddenness of onset of free fall. Acceleration doesn't build up gradually The building went from full support to zero support, instantly. One moment, the building is holding; the next moment it lets go and is in complete free fall. [93]
Still further evidence is provided, Chandler said, by another fact about WTC 7's descent:
The onset of free fall was not only sudden; it extended across the whole width of the building ... .The fact that the roof stayed level shows the building was in free fall across the entire width. The collapse we see cannot be due to a column failure, or a few column failures, or a sequence of column failures. All 24 interior columns and 58 perimeter columns had to have been removed ... simultaneously, within a small fraction of a second. [94]
Having made that point -- which is surely the clearest proof that explosives of some sort were used to remove the columns -- Chandler emphasized the importance of recognizing the deceptiveness of NIST's three-stage analysis:
We saw [earlier] that the 5.4 seconds depends on an artificially early start time which has no valid observational basis. Without the 5.4 second fig-leaf, we're left with freefall and nothing more. [95]
Finally, pointing out the contradiction between NIST's collapse model and the empirical fact that WTC 7 was in free fall for over two seconds -- which NIST has reluctantly admitted -- Chandler concluded:
One fact we do know about NIST's model is: it does not allow for free fall. ... There is nothing in the models we have been shown that even resembles a 3-stage collapse with a free-fall component. After all, as Shyam Sunder put it himself, "Free fall happens only when there are no structural components below the falling section of the building." Any natural scenario is going to involve a progression of failures, and these don't happen instantaneously. [96]
In other words, by admitting "a free-fall component," NIST has ended up with a self-contradictory position. On the one hand, its Final Report offers the same theory of WTC 7's collapse that was contained in its Draft Report, which was a theory of progressive collapse, in which the building's supports failed sequentially. On the other hand, NIST's Final Report concedes that the building came down part of the time in free fall, which means that all of the supports had to have failed simultaneously.
Given this contradiction at the very heart of the final version of NIST's theory, Shyam Sunder should be asked by the press whether he still stands by his confident assertion at the August 2008 press briefing that, thanks to NIST's analysis, "the reason for the collapse of World Trade Center 7 is no longer a mystery." [97] Far from solving the mystery of WTC 7's collapse, NIST has -- by continuing to provide a non-demolition theory of this collapse while admitting that it involved over two seconds of complete free fall -- built an absolute mystery into the official explanation.
Sunder also needs to be asked whether he still stands by his statement, made on that same occasion, that "science is really behind what we have said." [98] If he still believes this, why are all of NIST's previous claims that its analysis is "consistent with physical principles" missing in the final version of its report?
These claims had to be removed, of course, because Sunder and his fellow scientists at NIST know that the 2.25-second period of free fall they have admitted is not consistent with physical principles. Outdoing the cartoon mentioned in Chapter 2, these NIST scientists presented 606 pages of descriptions, testimonies, photographs, graphs, analyses, mathematical formulae, and explanations, after which they in effect said on page 607: "Then a miracle happens."
The Compact Debris Pile
Having shown that NIST's theory of progressive collapse cannot do justice to the actual collapse of WTC 7, as observed on videos, I will conclude this chapter by showing that this theory also cannot explain the result: a very compact debris pile, no more than two stories high, that was almost entirely within the building's footprint. (Photos showing this very tidy pile of rubble, situated cleanly between the neighboring buildings, are available on the internet. [99])
Phillip Tompkins, whose comment to NIST about its picture of the collapse was quoted above, also drew attention to this problem, writing: "I do not see how [NIST] explains the contents of the pile at the end of the collapse. Where and in what condition were all the long core columns?" [100]
I myself had raised this problem -- about all of the columns, not only the core columns -- in an earlier book. Having quoted the statement by New York Times writer James Glanz that, if the collapse of WTC 7 had not been overshadowed by that of the Twin Towers, it would have been "a mystery that ... would probably have captured the attention of the city and the world," [101] I wrote:
One of the biggest elements of this mystery is how this 47-story building's 81 columns -- 24 core and 57 perimeter columns -- could have collapsed into a very compact pile of rubble without being sliced by explosives. [102]
My statement contained two errors: First, although there were indeed 24 interior columns, only 21 of them were core columns (the other three -- Columns 79, 80, and 81 -- were in the eastern region of the building); second, there were 58 perimeter (exterior) columns, not 57, hence a total of 82 columns. [103] Correcting these two errors does not, however, affect the problem raised by my statement: Given the existence of all those columns, how could virtually all of the debris from the collapse have ended up in the building's footprint?
Here is the problem: WTC 7 was 610 feet high, so each column was 610 feet long. According to NIST's theory, the columns all buckled between the 7th and 14th floors, [104] after which "the entire building above the buckled-column region moved downward as a single unit." [105] Even if all of the columns buckled exactly at the 14th floor, the unbroken sections from the upper 33 floors would have been 429 feet long (each floor was 13 feet high).
Could these 429-foot-long columns have all come down into WTC 7's footprint? The building, which had a trapezoidal shape, was 247 feet long on the south side, 329 feet long on the north side, and about 150 feet on the east and west sides. [106] So even if all the columns had been placed in the middle of the footprint with their ends pointing east and west, they would not have fit within the footprint.
The columns, moreover, would not have come down so neatly. Many would have fallen outside the footprint in various directions, blocking the streets and destroying numerous nearby buildings, especially the Federal Building and the New York Telephone Building, which were very close to WTC 7. [107] That, however, did not happen -- which means that the columns must have been broken into smaller segments before they came down.
The compact pile of debris that resulted from the collapse of WTC 7 is what would be expected from the kind of controlled demolition known as "implosion," in which explosives are used to cut the steel columns in the right places and in the right order to make the building fold in on itself. During an interview in 1996, Stacey Loizeaux -- daughter of Mark Loizeaux, the president of Controlled Demolition, Inc. -- explained how it is done:
Depending on the height of the structure, we'll work on a couple different floors -- usually anywhere from two to six. The taller the building, the higher we work. We only really need to work on the first two floors, because you can make the building come down that way. But we work on several upper floors to help fragment debris for the contractor, so all the debris ends up in small, manageable pieces. [108]
There is, accordingly, an obvious explanation for the fact that WTC 7 collapsed into a relatively small pile of debris, with "small, manageable pieces" of steel. This is the same explanation that would account for the melted and sulfidized steel, the thermite residue in the dust, the reports of explosions in the building, and the rapid, straight-down collapse of the building, with over two seconds of absolute free fall. This is, in other words, the explanation that scientists guided by Occam's razor would have chosen.
NIST, however, refused to entertain this obvious explanation. As a result, it could not explain why the area surrounding the site of WTC 7 was not littered with 82 columns that were each at least 429 feet long. It simply ignores the problem, evidently hoping that no one -- at least no one who matters, such as the press or the next administration's Department of Justice -- would notice.
* * *
Every aspect of NIST's theory of a fire-induced global collapse of WTC 7, we have seen, depends on implausible claims and outright fabrications. Its theory of weakened floor beams depends on implausible steel temperatures, which in turn depend on implausible fire temperatures and durations. Its theory of thermally induced girder failure depends on two cases of fraud: denying the existence of shear studs and fabricating a "differential thermal expansion" in its computer simulation by heating the steel beams but not the floor slabs. Its theory of how thermally expanded beams wreaked havoc presupposes an implausible amount of elongation.
And yet, even with all of these fabrications and implausibilities, NIST ends up with a theory that cannot explain several obvious features of WTC 7's collapse: that the building's roofline remained essentially horizontal, that its upper floors came down in free fall for over two seconds, and that its debris ended up in a tidy pile, with most of it contained within the building's footprint.