The collapse of 7 World Trade Center was not a controlled demolition.

by Brian Dunning

Filed under Conspiracy Theories

Skeptoid Podcast #85

January 29, 2008

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https://skeptoid.com/audio/skeptoid-4085.mp3

Today we're going to point our skeptical eye, once again, at the events of September 11, specifically at World Trade Center 7, the building that collapsed after the twin towers for no apparent reason, in a manner consistent with a controlled demolition. We're entering the weird wild and wacky world of conspiracy theories, men in black, deceit, doubt, mistrust, and delusion. But on which side?

First let's be clear about what the two sides are, then we'll examine the evidence supporting each of them.

The conspiracy theory states that World Trade Center 7 was a controlled demolition, an intentional destruction of the building by our government. The evidence supporting this theory is threefold: First, the video of the collapse and the tidy distribution of the resultant debris appear consistent with known controlled demolitions. Second, photographs of the building before it collapsed showed little or no damage to cause a collapse. Third, fire alone cannot destroy a steel building, and so the cause must lie in high-energy explosives. A great deal more information is put forward by the supporters of this theory as evidence, but it's really only suppositions about proposed motives and observations of events perceived as unusual, and so is actually not testable evidence of a direct physical cause. This information includes government offices located in the building, the establishment of Giuliani's emergency management headquarters on the 23rd floor, and portions of the government's preliminary reports that openly stated that certain unknowns remained.

The competing theory is found in those very same government reports. The first, a preliminary report issued by the Federal Emergency Management Agency (FEMA) only eight months after the event, concluded that fires on the 5th through 7th floors caused the collapse, but infamously noted:

The specifics of the fires in WTC 7 and how they caused the building to collapse remain unknown at this time. Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence. Further research, investigation, and analyses are needed to resolve this issue.

Three years later, the National Institute of Standards and Technology (NIST) issued a working draft of the complete theory, scheduled to be finished in 2008. This report states that the building suffered two major failures, either of which could have been survived on its own, but not in combination. The first failure was severe damage to ten stories of the south side of the building, dramatically shown in a single frame of video from an ABC news helicopter, which destroyed several major columns. The second failure was the fire, fed in part by diesel generator fuel from high pressure tanks, which proceeded unfought for seven hours due to a lack of water pressure, and caused terminal weakening in the remaining columns that were already overloaded from the loss of the initial columns. Firefighters noted a growing bulge between the 10th and 13th floors and major structural creaking sounds, and finally evacuated. Two hours later, the east wall began to crack and bow. The east penthouse sank into the structure, and eight seconds later, the northeast corner fell, bringing the rest of the building down on top of it.

No evidence of any explosives were ever found, but the conspiracy theory states that this is because the government took away all the debris before it could be independently tested. Since it's normal for debris to be removed following any such destruction, this particular piece of information is too ambiguous to be given serious weight as proof of a conspiracy.

The claim that fire has never before destroyed a steel-framed building seems to hold up well, as it's hard to find a recent example of it. The reason is that modern building fires are always fought, they have sprinkler systems, and their steel is well insulated. Turn the clock back a few decades to World War II, when there was massive worldwide incendiary bombing of major cities, there were no sprinkler systems, and fire fighters had no hope of responding, there were many hundreds of steel framed buildings that were destroyed by fire. Not by bombs; by fire. The Edo Museum in Tokyo has preserved gnarled masses of giant girders twisted into knots by fire. London's Imperial War Museum has thousands of photographs of the same, and even a large collection of contemporary art depicting warped steel girders. Dresden's City Historical Museum also shows examples of steel girders from buildings that collapsed from fire, during that city's most infamous of all large-scale incendiary attacks. These museum collections all predate any alleged September 11 conspiracy.

There are three videos of the actual collapse that are of decent quality, and all show a collapse that appears reasonably consistent with what most laypeople have seen of controlled demolitions on television. The most obvious difference is that controlled demolitions start with multiple series of minor explosions distributed throughout the building to cut various support structures in a carefully planned sequence, followed a few seconds later by the charges to blow the key structural elements in a sequence designed to initiate the collapse in the desired direction. None of the videos of Building 7's collapse show any minor explosions. They simply show the top of the building begin to gracefully sag, as if it's made of clay, and then the whole thing drops. So while the manner of collapse may look superficially similar to a controlled demolition at first glance, a more careful examination shows critically important (and non-ambiguous) differences.

The neat, tidy arrangement of the debris of Building 7 is another characteristic of controlled demolitions that is claimed by the conspiracy theorists. WTC7.net states that "The pile was almost entirely within the footprint of the former building." In fact, Building 7's debris field was neither tidy nor well-contained within the footprint. The videos of the collapse are all from far away and show only the top portion of the building before it disappears behind the skyline. Lower down, the collapse become much more chaotic. Two nearby buildings were nearly destroyed by it. The Verizon Building suffered $1.4 billion in damage from the collapse of Building 7, but was able to be repaired. Manhattan Community College's Fiterman Hall building, however, was not so lucky, and suffered such major damage that it could not be saved. What remains of it is still being deconstructed piece by piece.

Could a building with such little apparent external damage collapse like this? The photos and videos on the conspiracy theory websites are from other angles, and show only relatively minor, superficial damage to the building; and even the NIST has said the fire alone would probably would not have destroyed the building. But, let's not forget that Building 7 did have damage: Severe damage, a deep gouge cutting a quarter of the way through the building, ten floors high. Yet even if there was such extensive damage, argue the conspiracy theorists, that fact alone would invalidate the government report. Also from WTC7.net:

"The alleged damage was asymmetric, confined to the tower's south side, and any weakening of the steelwork from fire exposure would also be asymmetric. Thus, even if the damage were sufficient to cause the whole building to collapse, it would have fallen over asymmetrically — toward the south."

This claim forgets that nobody has said the damage alone was responsible for the collapse. According to the NIST report, the initial loss of the columns served only to transfer the building load to the remaining columns, thus exceeding their load bearing capacities, which then gave way after being adequately softened by the fire. In such a condition, the building would have insufficient support throughout. The east side, already sagging, dropped first and pulled the rest of the building down in a slightly diagonal collapse. The conspiracy theorists are correct in that the fall was not entirely symmetric, as it strayed enough to do the aforementioned damage to the Verizon and Manhattan Community College buildings. The conspiracy theorists have hardly proven that explosives are the only possible explanation for the collapse.

There's really nothing that's either mysterious or unexpected about the manner of Building 7's collapse. It was doomed by the damage, the diesel-fed fires, and the lack of firefighting capability. All the physical evidence, photographic evidence, and testimony of the firefighters is perfectly consistent with the government's official report. The conspiracy theory is supported by no evidence and is inconsistent with all of the events in the 7 hours preceding the collapse. The cause of Building 7's collapse is a question where very little critical analysis needs to be applied by a rational person. Judge the evidence for yourself.



By Brian Dunning

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