Collapse of WTC7

This book is a technical evaluation of the work carried out by the US National Institute for Standards and Technology and Professor Bailey at Queen Mary College, London. The work raised many questions, questions which, for the writer as an engineer, needed answers. Fundamentally the question was how the conclusion that office fires were responsible for the building’s collapse was reached, when: - No one apparently witnessed burning debris entering WTC7 floors through its windows. - Fires didn’t burn long enough and hot enough for the integrity of steelwork to be compromised. - Steelwork debris was not analysed to determine temperatures reached because it was disposed of prematurely. - No-one witnessed the collapse initiating event and subsequent progression of collapse (no-one, unsurprisingly, was inside the building at the time) yet detailed conclusions were drawn as to the sequence of structural failure events that lead to total collapse and was therefore due to office fires.