I get really tired of the "scratch our noses around our elbows" conspiracy theories being constantly pounded.
So let me answer your question, T2H.
"Does anyone seriously believe that these three steel framed buildings collapsed to dust near or at free-fall speed, due to office fires and jet fuel?"
Except for the fact that they were steel-and-concrete, and they collapsed to dust-and-wreckage, YES, I do. And I am NOT a Professional Engineer, but I do have a BS in engineering, and have used those engineering skills for a long time now.
I do bridges, not buildings (except for the piles which are common to both). But the principles are the same. And they are Steel and Concrete bridges, just like the buildings.
You should have seen the video of when we had to demolish one of our girders. It would have looked like a conspiracy, because as they crunched it in the middle, the thing stood strong, until they got the drape strand. All of a sudden, the whole thing – 180' of it – developed vertical cracks, every 20', nowhere near the site of the demolition.
If you knew what was going on inside the girder, it wouldn't have surprised. But the point is… things don't always follow a layman's reasoned theories of what should happen.