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Context of 'December 14, 2007: NIST Fact Sheet Responds to Questions about Its WTC Investigation'

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Michael Burton.Michael Burton. [Source: PBS]Following the World Trade Center collapses, a decision is made to quickly transport the remaining structural steel to scrap yards, to be shipped abroad and melted down for reuse. Consequently, virtually all of it is disposed of before investigators trying to assess why the WTC collapsed can examine it. Michael Burton and other officials at the Department of Design and Construction—the New York City agency overseeing the cleanup operation (see (September 11, 2001-May 2002))—are responsible for making this decision. Burton clears it with Richard Tomasetti of Thornton-Tomasetti Engineers, the prime consultant on the cleanup job. However, referring to the subsequent WTC investigation by the National Institute of Standards and Technology (see August 21, 2002), Tomasetti will later admit that had he known the direction that investigations into the collapses would take, he would have taken a different stand. (Langewiesche 2002, pp. 30; Glanz and Lipton 2004, pp. 330 and 396) Authors and New York Times reporters James Glanz and Eric Lipton write that Michael Burton, “who had become the effective czar for the cleanup job, had made it clear that he cared very little about engineering subtleties like the question of why the towers first stood, then collapsed on September 11. ‘We know why they fell,’ he said. ‘Because they flew two planes into the towers.’ But he was deeply immersed in the details of hauling steel out of the debris pile.” (Glanz and Lipton 2004, pp. 299) Much of the WTC steel will be shipped to India, China, and other Asian countries for recycling (see September 12-October 2001).

The New York Times reports that “some of the nation’s leading structural engineers and fire-safety experts” believe the investigation into the collapse of the WTC is “inadequate” and “are calling for a new, independent and better-financed inquiry that could produce the kinds of conclusions vital for skyscrapers and future buildings nationwide.” Experts critical of the investigation include “some of those people who are actually conducting it.” They point out that the current team of 20 or so investigators has no subpoena power, inadequate financial support, and little staff support. Additionally, it has been prevented from interviewing witnesses and frequently prevented from examining the disaster site, and has even been unable to obtain basic information like detailed blueprints of the buildings that collapsed. The decision to recycle the steel columns, beams, and trusses from the WTC rapidly in the days immediately after 9/11 means definitive answers may never be known. (Glanz and Lipton 12/25/2001) Incredibly, some of the steel is reforged into commemorative medallions selling for $30 apiece. (Associated Press 1/30/2002)

A firefighter trade magazine with ties to the New York Fire Department calls the investigation into the collapse of the WTC a “half-baked farce.” The article points out that the probe has not looked at all aspects of the disaster and has had limited access to documents and other evidence. “The destruction and removal of evidence must stop immediately.” The writer, Bill Manning, states, “I have combed through our national standard for fire investigation, NFPA 921, but nowhere in it does one find an exemption allowing the destruction of evidence for buildings over 10 stories tall.” He concludes that a growing number of fire protection engineers have theorized that “the structural damage from the planes and the explosive ignition of jet fuel in themselves were not enough to bring down the towers.” Yet, “[a]s things now stand and if they continue in such fashion, the investigation into the World Trade Center fire and collapse will amount to paper- and computer-generated hypotheticals.” (Manning 1/2002; Calderone 1/4/2002)

During the course of its three-year investigation of the World Trade Center collapses, the National Institute of Standards and Technology (NIST) performs computer simulations of the behavior of each WTC tower on 9/11. In its final report, released in October 2005 (see October 26, 2005), it will describe having determined which variables most affected the outcome of its various simulations. Then, “[f]or each of the most influential variables, a central or middle value and reasonable high and low values were identified.” However, “[u]pon a preliminary examination of the middle cases, it became clear that the towers would likely remain standing. The less severe cases were discarded after the aircraft impact results were compared to observed events. The middle cases… were discarded after the structural response analysis of major subsystems were compared to observed events.” Therefore, the “more severe case… was used for the global analysis of each tower.” But, to “the extent that the simulations deviated from the photographic evidence or eyewitness reports, the investigators adjusted the input, but only within the range of physical reality.” (National Institute of Standards and Technology 9/2005, pp. 143-144)

The 43 NIST reports ran to over 10,000 pages.The 43 NIST reports ran to over 10,000 pages. [Source: NIST]The National Institute of Standards and Technology (NIST) issues the final report of its three-year, $16 million study into the WTC collapses on 9/11. NIST has produced over 10,000 pages of findings, and its report includes 30 recommendations for improving building safety, such as having wider stairwells and structurally hardened elevators for use in emergencies. The recommendations are mostly the same as those outlined in an earlier draft of the report (see June 23, 2005). (Ichniowski 10/27/2005; Lipton 10/27/2005) NIST has made some amendments and clarifications, though, based upon nearly 500 comments received during a six-week public review period. (National Institute of Standards and Technology 10/26/2005) NIST’s theory about what caused the Twin Towers to collapse remains the same as that described in its previously released findings (see October 19, 2004). However, the NIST’s account only examines events up to the initiation of each collapse; the investigation “does not actually include the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable.” (National Institute of Standards and Technology 9/2005, pp. 82) NIST makes no mention of molten metal found at the collapse site in the weeks and months after 9/11, which has been described in numerous reports (see September 12, 2001-February 2002). The “NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001.” (National Institute of Standards and Technology 9/2005, pp. 146) Members of Congress are critical of NIST’s recommendations, saying they are not detailed enough, or adequately documented, to be rapidly incorporated into standard building code publications. (Lipton 10/27/2005) According to Glenn Corbett, a technical adviser to NIST and fire science professor at John Jay College, NIST is not aggressive enough to carry out major forensic investigations. He says, “Instead of a gumshoe inquiry that left no stone unturned, I believe the investigations were treated more like research projects in which they waited for information to flow to them.” (Barrett 10/26/2005; US Congress 10/26/2005 pdf file) NIST will release its final report on the collapse of Building 7 of the WTC separately, at a later date. (National Institute of Standards and Technology 9/2005, pp. xiii)

One of the ‘puffs of smoke’ observed during the Twin Towers collapses.One of the ‘puffs of smoke’ observed during the Twin Towers collapses. [Source: Richard Lethin]The National Institute of Standards and Technology (NIST) issues a seven-page fact sheet to counter alternative theories about the WTC collapses. NIST conducted a three-year study of the collapses, and concluded they were caused by the damage when the planes hit combined with the effects of the ensuing fires. However, many people—what the New York Times calls an “angry minority”—believe there was US government complicity in 9/11, and a recent poll (see July 6-24, 2006) found 16 percent of Americans believe the WTC towers were brought down with explosives. (National Institute of Standards and Technology 8/31/2006; Dwyer 9/2/2006; Wolf 9/2/2006) The fact sheet responds to 14 “Frequently Asked Questions.” Some of its key points include the following:
bullet Regarding whether NIST considered a controlled demolition hypothesis: “NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down… using explosives… Instead, photographs and videos from several angles clearly show that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward until the dust clouds obscured the view.” However, it admits, “NIST did not test for the residue” of explosives in the remaining steel from the towers.
bullet Its explanation for puffs of smoke seen coming from each tower as it collapsed: “[T]he falling mass of the building compressed the air ahead of it—much like the action of a piston—forcing smoke and debris out the windows as the stories below failed sequentially.”
bullet Its explanation for a stream of yellow molten metal that poured down the side of the South Tower shortly before it collapsed (see (9:50 a.m.) September 11, 2001). NIST previously claimed it was aluminum, but this should not have been yellow in color: “Pure liquid aluminum would be expected to appear silvery. However, the molten metal was very likely mixed with large amounts of hot, partially burned, solid organic materials (e.g., furniture, carpets, partitions and computers) which can display an orange glow.”
bullet Regarding reports of molten steel in the wreckage at Ground Zero (see September 12, 2001-February 2002): “Any molten steel in the wreckage was more likely due to the high temperature resulting from long exposure to combustion within the pile than to short exposure to fires or explosions while the buildings were standing.”
bullet Regarding the collapse of WTC 7 (see (5:20 p.m.) September 11, 2001): “While NIST has found no evidence of a blast or controlled demolition event, NIST would like to determine the magnitude of hypothetical blast scenarios that could have led to the structural failure of one or more critical elements.” (National Institute of Standards and Technology 8/30/2006) In response to the fact sheet, Kevin Ryan, the coeditor of the online Journal of 9/11 Studies, says, “The list of answers NIST has provided is generating more questions, and more skepticism, than ever before.” He says, “NIST is a group of government scientists whose leaders are Bush appointees, and therefore their report is not likely to veer from the political story.” (Dwyer 9/2/2006; Wolf 9/2/2006)

The National Institute of Standards and Technology (NIST) publishes a fact sheet responding to 14 “frequently asked questions” about its investigation into the collapse of the Twin Towers on September 11. Some of the key questions and answers are as follows:
bullet Regarding the question, “Why was the collapse of WTC 1 and 2 not arrested by the intact structure below the floors where columns first began to buckle?” NIST replies, “The vertical capacity of the connections supporting an intact floor below the level of collapse was adequate to carry the load of 11 additional floors if the load was applied gradually and 6 additional floors if the load was applied suddenly (as was the case).” As the number of floors above the points where the collapses initiated exceeded six (12 in the case of the North Tower, 29 for the South), NIST says, “[T]he floors below the level of collapse initiation were unable to resist the suddenly applied gravitational load from the upper floors of the buildings.”
bullet In answer to the question of “Why was physical evidence not collected immediately following the collapse of the WTC towers,” NIST says, “In the initial days and weeks following the WTC disaster, the emphasis was on rescue and later on recovery, necessitating the removal of steel and disturbing the collapse site.” It adds, “NIST did not receive the legal authority to collect and preserve physical evidence from a disaster/failure site until the National Construction Safety Team Act became law in October 2002.” The decision to rapidly scrap the remaining steel from the WTC was made shortly after 9/11 (see Shortly After September 11, 2001), but the destruction of this steel was strongly protested by some within the engineering and firefighting communities (see December 25, 2001 and January 4, 2002).
bullet In response to a question about why it did not use its subpoena authority during its investigation, NIST states that its “experience during the investigation was that it was able to obtain all essential documentary and visual evidence without the need to invoke subpoena authority.”
bullet In answer to the question, “Why didn’t NIST fully model the collapse initiation and propagation of WTC towers?” NIST says, “Once the collapse had begun, the propagation of the collapse was readily explained without the same complexity of modeling” as was used to determine the sequence of events leading up to the collapse initiation.
bullet During its investigation, NIST had selected several variables for its computer simulations, and then experimented with different possible values (see (October 2002-October 2005)). But it has been asked: “Why didn’t NIST consider the ‘base’ and ‘less severe’ cases throughout its analysis of the WTC towers? What was the technical basis for selecting only the ‘more severe’ case for its analyses?” Its answer is that, “Of the three [possible values], the more severe case resulted in the closest agreement with the visual and physical evidence.” (National Institute of Standards and Technology 12/14/2007)
NIST published its final report on the Twin Towers collapse in October 2005 (see October 26, 2005). It released an earlier fact sheet answering previous “frequently asked questions” in August 2006 (see August 30, 2006). (National Institute of Standards and Technology 8/30/2006)

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