Like I said, Popular Mechanics is right when they say that structural weakening can be caused by the warping of the support columns, not their melting. But this doesn't create a free-fall straight down into the building's own footprints. It would fall unevenly because the fires are uneven. And plus, the fires were at the top so a full collapse of the building is highly unlikely even if there was warping going on.

Like I said, Popular Mechanics doesn't mention the fact that pools of molten steel were found in the basements. And distinct traces of thermate was found in the residue, proving the existence of an incendiary. Don't simply re-quote Popular Mechanics, that doesn't get us anywhere because I already read it, and I already pointed out the things it left out for it's convenience as you asked.

And in fact Popular Mechanics only hurts its own argument because they were asserting steel doesn't melt in building fires. And had credible people quote that steel doesn't melt in building fires. Yet melted steel was found.