speaking in support of Richard Gage and Architects & Engineers for 9/11 Truth at an event in Los Angeles Members of the organization argue that the buildings of the World Trade Center could not have collapsed only because of the impact of the planes, or as a result of the fires that had been caused by them. On the one hand Gage has said that avoiding speculation on the attacks on the Pentagon or on the involvement of the Bush administration is critical to the mission of the organization. But on the other hand, Gage has said that if the destruction of the World Trade Center was the result of a controlled demolition, this would mean that part of what happened on September 11, 2001, would have been planned by "some sort of an inside group". According to Gage, an elevator modernization program that had taken place before the attacks would have provided an opportunity to get access to the core areas of the WTC towers without creating suspicion. Investigations by the
Federal Emergency Management Agency and the
National Institute of Standards and Technology (NIST) have concluded that the buildings collapsed as a result of the impacts of the planes and of the fires that resulted from them. In 2005, a report from NIST concluded that the destruction of the World Trade Center towers was the result of
progressive collapse initiated by the jet impacts and the resultant fires. A 2008 NIST report described a similar progressive collapse as the cause of the destruction of the third tallest building located at the
World Trade Center site, the
7 World Trade Center. Many mainstream scientists choose not to debate proponents of 9/11 conspiracy theories, saying they do not want to lend them unwarranted credibility. The NIST explanations of the collapses are universally accepted by the structural-engineering and structural-mechanics research communities.
World Trade Center towers Gage criticized NIST for not having investigated the complete sequence of the collapse of the World Trade Center towers, and claims that "the official explanation of the total destruction of the World Trade Center skyscrapers has explicitly failed to address the massive evidence for explosive demolition." In particular, Gage argues that the buildings of the World Trade Center could not have collapsed at the speed that has been observed without tearing apart several columns of their structures with the help of explosives. That the three buildings of the World Trade Center "fell through what should have been the path of greatest resistance" would, according to the organization, require "precisely timed removal of critical columns, which office fires cannot accomplish". Gage maintains that the "sudden and spontaneous" collapse of the towers would have been impossible without a controlled demolition, that pools of molten iron found in the debris of the buildings were evidence of the existence of
thermite, and that researchers had found unignited
nano-thermite in the dust produced by the collapse of the World Trade Center. Gage argues that this material "is not made in a cave in Afghanistan". Iron-rich micro-spheres, which, according to the organization, have been found in the dust of the World Trade Center buildings by independent laboratory analyses, would indicate temperatures during the collapses much higher than temperatures that would result from hydrocarbon fires. In 2008,
Zdeněk P. Bažant, professor of
civil engineering and
materials science at
Northwestern University, published with three coauthors a paper to examine whether allegations of controlled demolition might be scientifically justifiable. They found that the available video records are not consistent with the free fall hypothesis, that the size of the concrete particles is consistent with
comminution caused by impact, and that the high velocity of compressed air explains why material from the towers were ejected to a distance of several hundred meters from the tower. The authors conclude that the allegations of controlled demolition do not have any scientific merit. A spokesman for NIST said that any sightings of molten metal, including metal seen pouring from the South Tower, were likely molten aluminum from the airplane, an explanation disputed by Gage who stated that the color of the molten metal rules out aluminum. Gage also described 7 WTC as "the most obvious example of controlled demolition." According to Gage, the only way to bring a building down with free-fall acceleration would be to remove its columns, which provide resistance to the force of gravity. Scott Grainger, a
fire protection engineer and member of the group, told the BBC that the evidence he had seen indicated the fires in 7 WTC were scattered about on the floors and would have moved on as they would have found no more combustibles. He thus claims that the fires could not have developed enough heat to cause the collapse of the building. "Buildings that fall in natural processes fall to the path of least resistance," says Gage, "they don't go straight down through themselves." Architects & Engineers for 9/11 Truth also questions the computer models used by NIST, and argues that evidence pointing to the use of explosives had been omitted in its report on the collapse of 7 WTC. The community of experts in
structural mechanics and
structural engineering generally supports the explanation of the collapse of the World Trade Center buildings provided by the investigation conducted by NIST. In the case of 7 WTC, the appearance of a controlled demolition can be explained by an interior failure of the building, which is suggested by the sequence of the collapse of 7 WTC that shows roof elements sinking into the building while the façade remained intact.
Criticism of the official investigations Architects & Engineers for 9/11 Truth has expressed concerns that evidence related to the destruction of the World Trade Center could have been distorted and covered up by the
National Institute of Standards and Technology (NIST), which conducted a
building and fire safety investigation, one of the official investigations into the event. According to the group, and NIST themselves (who considered it unnecessary), NIST did not look for physical evidence of explosives, and leaders of Architects & Engineers for 9/11 Truth dismissed NIST's investigation as flawed. When told of the claims, Shyam Sunder, lead investigator from NIST, responded: "I am really not a psychologist. Our job was to come up with the best science." == References ==