3. The Destruction of WTC 1 and WTC 2

This chapter provides an overview of the evidence regarding the structural behavior of WTC 1 and WTC 2 during their destruction. The features of their behavior that will be examined include the onset of collapse, the downward acceleration of the upper sections, the manner in which the buildings’ materials were destroyed, the high velocity bursts of debris (“demolition squibs”) seen during collapse, and eyewitness accounts of the destruction.

In the last chapter, we examined the official investigations conducted by FEMA and NIST and found that instead of starting with the most likely hypothesis — which we have established as controlled demolition — investigators started with the hypothesis of fire-induced failure. They then clung to that hypothesis to the end, considering and rejecting various versions of it over several years, and, in the case of FEMA’s WTC 7 investigation, acknowledging that their best hypothesis had only a low probability of occurrence.

We will now examine the evidence regarding the structural behavior of WTC 1 and WTC 2 during their destruction (WTC 7 will be covered in the next chapter) and evaluate whether it is more consistent with the hypothesis of fire-induced failure advanced by NIST or with the hypothesis of controlled demolition. To guide our evaluation of these competing hypotheses, we now turn to a third principle that is fundamental to the scientific method. David Ray Griffin describes it as follows: “None of the relevant evidence should be ignored.”1 This principle is of central importance in evaluating the official hypothesis.

For, as we will see below, NIST ignored a large amount of the relevant evidence by stopping its analysis at the point of “collapse initiation.” Instead of providing an explanation for what actually happened — the observed behavior of the buildings during their destruction — NIST limited the scope of its investigation