Five years later they still only have a 'working collapse hypothesis' for WTC 7 based on the OCT version of what happened. That's not much to go on is it? Especially, since they've still haven't done a proper investigation into WTC7 and most of the evidence has been destroyed by now.
14. Why is the NIST investigation of the collapse of WTC 7 (the 47-story office building that collapsed on Sept. 11, 2001, hours after the towers) taking so long to complete? Is a controlled demolition hypothesis being considered to explain the collapse?
When NIST initiated the WTC investigation, it made a decision not to hire new staff to support the investigation. After the June 2004 progress report on the WTC investigation was issued, the NIST investigation team stopped working on WTC 7 and was assigned full-time through the fall of 2005 to complete the investigation of the WTC towers. With the release and dissemination of the report on the WTC towers in October 2005, the investigation of the WTC 7 collapse resumed. Considerable progress has been made since that time, including the review of nearly 80 boxes of new documents related to WTC 7, the development of detailed technical approaches for modeling and analyzing various collapse hypotheses, and the selection of a contractor to assist NIST staff in carrying out the analysis. It is anticipated that a draft report will be released by early 2007.
The current NIST working collapse hypothesis for WTC 7 is described in the June 2004 Progress Report on the Federal Building and Fire Safety Investigation of the World Trade Center Disaster (Volume 1, page 17, as well as Appendix L), as follows:
* An initial local failure occurred at the lower floors (below floor 13) of the building due to fire and/or debris-induced structural damage of a critical column (the initiating event) which supported a large-span floor bay with an area of about 2,000 square feet;
* Vertical progression of the initial local failure occurred up to the east penthouse, and as the large floor bays became unable to redistribute the loads, it brought down the interior structure below the east penthouse; and
* Triggered by damage due to the vertical failure, horizontal progression of the failure across the lower floors (in the region of floors 5 and 7 that were much thicker and more heavily reinforced than the rest of the floors) resulted in a disproportionate collapse of the entire structure.
This hypothesis may be supported or modified, or new hypotheses may be developed, through the course of the continuing investigation. NIST also is considering whether hypothetical blast events could have played a role in initiating the collapse. While NIST has found no evidence of a blast or controlled demolition event, NIST would like to determine the magnitude of hypothetical blast scenarios that could have led to the structural failure of one or more critical elements.
http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htmI do agree with you that, the unique construction (transformer/truss layout) of the building and generator fuel system that may have doomed it from the start. However, none of the generator fuel system was part of the original design and was all installed after the 1993 WTC Bombing.
Why would anyone run a pressurized fuel system that spanned the entire 5th Floor, the same floor that contained the unique truss system that held up the building and then not bother to install a fire suppression system for it?
Why did Rudy put his Office of Emergency Management in WTC7 only to abandon it before the Towers fell?
Why is it that 5 years later the NIST is starting to consider the possibility of an explosive event on the 5th - 7th Floors that may have brought down the building?
If an explosive event brought down the building, then it was not the damage from the collapse or the fires that were observed in various parts of the building that caused the failure, even though they may have contributed. Something else happened and NIST is still scratching their asses trying to figure it out.