26 stories; fire duration: 8 hours) ■■
Joelma Building in Sao Paulo, Brazil (height: 25 stories; fire duration: one hour and 40 minutes)
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Andraus Building in Sao Paolo, Brazil (height: 31 stories; fire duration: unknown)
The NIST survey also noted two major fire test programs conducted at the Building Research Establishment (BRE) Laboratories in Cardington, United Kingdom. The first series of tests, conducted on a representative eight-story composite steel-framed office building, resulted in significant fire damage but did not result in collapse, even with unprotected steel floors. The second series of tests conducted on a seven-story concrete building also did not result in collapse. Given the high frequency of fires in steel-framed high-rise buildings and the low frequency of fire-induced collapses, the probability when a fire occurs in a steel-framed high-rise building that it will result in a partial collapse is extremely low. The probability that it will result in a total collapse appears to be even lower.
The Features of Controlled Demolition vs. Fire-Induced Failure Let us now move from examining the occurrence of collapse to the manner of collapse produced by controlled demolition and fire-induced failure, respectively. Table 1 on the following page lists several common features that generally distinguish controlled demolitions and fire-induced failures. As Table 1 illustrates, the corresponding features of controlled demolition and fire-induced failure are virtually the opposite of each other. Not every controlled demolition exhibits all of the features of controlled demolition listed in Table 1, nor does every fire-induced failure exhibit all of the features of fire-induced failure listed in Table 1. However, there is very little crossover: When a building’s cause of collapse is controlled demolition, the building exhibits virtually none of the features of fire-induced failure. Similarly, when a building suffers a fire-induced failure, it exhibits virtually none of the key features of controlled demolition (with the exception
Let us take WTC 7 as an example. According to the official explanation, its collapse was due solely to normal office fires and not from structural damage caused by debris. The probability when WTC 7 caught fire that it would totally collapse as a result of those normal office fires was exceedingly low.
BEYOND MISINFORMATION
Fire damage in WTC 5 (2002 NIST survey of fires that resulted in total or partial collapse).
7
BRE tests in Cardington, United Kingdom.
Partial connection and floor failures in WTC 5 (2002 NIST survey of fires that resulted in total or partial collapse).
