This week the National Institute of Standards and Technology released its long awaited report on the collapse of WTC7, the smaller third building destroyed as a result of the attack on the World Trade Center on 9/11. The examination of the evidence is exhaustive and disproves every one of the bizarre conspiracy theories which have been circulated about the collapse of this building, which was not actually hit by the two jetliners used in the attack. At the heart of the report is the conclusion that after debris from the two larger buildings started fires on multiple floors of the WTC7, it was the failure of the building's sprinkler systems which allowed fires to run unchecked and led to the collapse.
The collapse of the two main WTC towers played two roles in the destruction of WTC7. First, flaming debris started fires on floors 7, 8, 9, 11, 12 and 13, which spread rapidly, feeding on office furniture, rugs and paneling. Second, the collapse of the main towers damaged both the primary and secondary connections to the city water supply so that the sprinkler system, which should have suppressed the fires, was no use at all. The fires then burned out of control for 7 hours, ultimately resulting in enough structural damage for the floors to start a pancake-style collapse, beginning with the 13th floor (there's some fuel for triskaidekaphobes).
The report is based on an exhaustive three year study which includes debris analysis, experiments with materials, actual fire testing and computer modeling. It goes over evidence which disproves all of the major alternative theories favored by conspiracy theorists, finding no support for claims that there was any kind of explosion or controlled demolition, and ultimately concluding that although collapses of buildings of this size have not happened before, what happened with WTC7 suggests that fire should be taken more seriously as a structural threat to larger buildings in the future, and includes recommendations for changes in building codes to prevent similar fires. Of course, very few fires combine multiple points of origin with massive damage to the infrastructure supporting the fire control sprinklers, a situation unique to the World Trade Center attack. Had the sprinklers operated properly, the fire would have done no more damage than is typical in other large building fires and the building would not have collapsed.
Not surprisingly, no amount of evidence will sway the psychotically obsessed truthers from their delusions. They are already describing the report as a "Cover Up" and the "Crime of the Century" — apparently an even greater crime than the attack on the World Trade Center itself. They are also making attempts to debunk the evidence, generally by aggressive repetition of arguments which are specifically addressed and disproven in the report, on the theory that if they shout more loudly they will win the argument by drowning out the evidence.
While the report provides exhaustive scientific and technical evidence to counter the claims which truthers have held dear for years, it is only part of the story. The theory that the collapse of WTC7 was a controlled demolition also fails to hold up on the basis of simple logic. There are basic questions which the truthers have never been able to answer adequately. For example, what was the motive for destroying WTC7 when the collapse of the two main towers was far more dramatic, and the destruction of WTC7 involved no loss of life or destruction of critical data or materials? Or, how was it possible to plant demolition charges in the building in a period of only 7 hours while hundreds of firefighters were working there, without one eyewitness seeing the charges or the people planting them, or the substantial removal of structural material necessary to place to charges on supporting columns?
Conspiracy claims about WTC7 have never made any sense, and the new NIST report ought to lay them to rest once and for all. Yet I'm sure it will take more than overwhelming evidence to calm the tide of pure delusion which drives the truthers.