Sorry for coming to the table so late in the life of this thread, but I just stumbled across it and felt compelled to respond.
Before relying on the NIST report as a source of authority and integrity, it may well be worth looking into the validity of the report itself. I did, as have others, and after cross referencing their findings with their methods of drawing their conclusions, I was left of the opinion that the entire report represents nothing more than a $20 million, 10,000 page exercise in obfuscation, data-fudging and evidence discarding.
Of course, I wouldn't expect you to take my word for it, so I highly encourage you to look into it for yourself. An excellent place to start would be with Kevin Ryan - an expert in his field (a former Site Manager for Underwriters Laboratories - the company that was responsible for signing off on the steel used in the WTC construction and therefore an expert metallurgist). His dissection of the NIST report makes for very interesting reading and viewing, and as long as you are approaching the subject without drawing any prior conclusions and still have an attitude of openness to the subject, I think you'll find it hard to come away from his critique without having at least a couple of substantial doubts about NIST's modus operandi.
You can find a detailed breakdown of a presentation he gave at the following link
http://911research.wtc7.net/reviews/kev ... elanalysis
There is an accompanying video, which I strongly recommend you take the time to view, which is hosted on youtube in multiple parts, and can be accessed here
As far as qualified and credible people go, few could be more qualified than John Skilling. He was the structural engineer in charge of the design of the WTC. If you are interested in what he had to say pre-911, then please peruse the following, taking note of the dates of the articles
http://community.seattletimes.nwsource. ... ug=1687698
"On Feburary 13, 1965, real estate baron Lawrence Wien called reporters to his office to charge that the design of the Twin Towers was structurally unsound. Many suspected that his allegation was motivated by a desire to derail the planned World Trade Center skyscrapers to protect the value of his extensive holdings, which included the Empire State Building. In response to the charge, Richard Roth, partner at Emery Roth & Sons, the architectural firm that was designing the Twin Towers, fired back with a three-page telegram containing the following details. 5
THE STRUCTURAL ANALYSIS CARRIED OUT BY THE FIRM OF WORTHINGTON, SKILLING, HELLE & JACKSON IS THE MOST COMPLETE AND DETAILED OF ANY EVER MADE FOR ANY BUILDING STRUCTURE. THE PRELIMINARY CALCULATIONS ALONE COVER 1,200 PAGES AND INVOLVE OVER 100 DETAILED DRAWINGS.
4. BECAUSE OF ITS CONFIGURATION, WHICH IS ESSENTIALLY THAT OF A STEEL BEAM 209' DEEP, THE TOWERS ARE ACTUALLY FAR LESS DARING STRUCTURALLY THAN A CONVENTIONAL BUILDING SUCH AS THE EMPIRE STATE BUILDING WHERE THE SPINE OR BRACED AREA OF THE BUILDING IS FAR SMALLER IN RELATION TO ITS HEIGHT.
5. THE BUILDING AS DESIGNED IS SIXTEEN TIMES STIFFER THAN A CONVENTIONAL STRUCTURE. THE DESIGN CONCEPT IS SO SOUND THAT THE STRUCTURAL ENGINEER HAS BEEN ABLE TO BE ULTRA-CONSERVATIVE IN HIS DESIGN WITHOUT ADVERSELY AFFECTING THE ECONOMICS OF THE STRUCTURE. ...
At the time the Twin Towers were built, the design approach of moving the support columns to the perimeter and the core, thereby creating large expanses of unobstructed floor space, was relatively new, and unique for a skyscraper. However, that approach is commonplace in contemporary skyscrapers.
Frank Demartini's Statement
Frank A. Demartini, on-site construction manager for the World Trade Center, spoke of the resilience of the towers in an interview recorded on January 25, 2001.
The building was designed to have a fully loaded 707 crash into it. That was the largest plane at the time. I believe that the building probably could sustain multiple impacts of jetliners because this structure is like the mosquito netting on your screen door -- this intense grid -- and the jet plane is just a pencil puncturing that screen netting. It really does nothing to the screen netting.
Demartini, who had an office on the 88th floor of the North Tower, has been missing since the 9/11/01 attack, having remained in the North Tower to assist in the evacuation. 6 Demartini had first worked at World Trade Center when Leslie E. Robertson Associates hired him to assess damage from the truck bombing in 1993"
You may also find the following enlightening
http://www.journalof911studies.com/arti ... hTemp2.pdf
http://www.journalof911studies.com/volu ... ssible.pdf
http://www.journalof911studies.com/volu ... Method.pdf
Hope this helps