No you don't really need it. If you were really interested, you wouldn't be asking me to post what was already posted (Post #111) on the prior page of this thread because it would have caught your attention upon an initial reading. But for those who missed it and are genuinely interested: The focus of the Investigation was on the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower. For brevity in this report, this sequence is referred to as the probable collapse sequence, although it includes little analysis of the structural behavior of the tower after the conditions for collapse initiation were reached. - Footnote 2, NCSTAR 1 page xxxvii, PDF page 39. http://ws680.nist.gov/publication/get_pdf.cfm?pub_id=909017 And as already explained, there is no evidence NIST did ANY analysis, never mind "little".