[QUOTE=ivan astikov]
I haven’t got the credentials to answer your question to the satisfaction of GD standards, and I’m only responding because you specifically address me. All I am suggesting is that IF it was at all possible to have brought those buildings down deliberately, the likelihood should AT LEAST be investigated. And there are obviously more than a few people who think the same way as me.
corrected for typo.
[/QUOTE]
Is it possible? Sure. Did the NIST investigate this possibility? Yes they did - see the “Q&A” link that I posted; about halfway down the page they specifically address questions about explosives and thermite. If you download the entire report (it’s two big honkin’ PDFs, one about 20mb and the other about 45mb) you’ll notice that one of the authors of the section regarding explosive demolition is from CDI (Controlled Demolition Incorporated) which is a very famous company responsible for probably most of the “blowin’ up buildings” videos that we see. Appendix D starts on page 683 of the report.
Alex, you mentioned in your first post that you’d like to see them address where the critical column failed - if you read the basic summary on NIST’s front page you will see that they do precisely that, discussing which column failed (#79, with accompanying diagram), where it failed (the 9-story section that lost lateral support due to floors collapsing), the failure mode (long-column buckling, that’s real basic stuff in structural engineering) and why the lateral support (floors) failed to begin with.
If you want a very simple demonstration of what happens when a column loses lateral stability try this: Take a plain wooden yardstick and put one end on the floor. Now press straight down on the other end with your hand until it bows out of shape. That’s a column buckling with a long unsupported span.
Now do it again, only this time grab the yardstick at the 18 inch mark with your free hand. Notice how much harder it is to make the yardstick buckle by pressing down on the top? That’s because you’ve cut the unsupported length in half which can result in up to four times the compressive strength (not exactly because there are multiple failure modes but you can see the dramatic difference that one support makes). Imagine how different it’d be if that yardstick was braced every four inches (nine “floors”) compared to only being held at the two ends (nine “floors” removed).
If you want to plow through their math, computer simulations, diagrams and all the other chewy stuff I advise making up a nice pot of coffee and reading through the report - it’s over 700 pages long so it may take an evening or two to digest 
For the people that my OP was addressed to, that being folks who did not accept the common explanation of structural failure brought about by fires and physical damage initiated by the collapse of WTC1 and 2, have you read the NIST report, or at least the summary and if so did that change your position at all? If you haven’t read it, please do so. If you don’t want to read it then my OP isn’t really aimed at you.