[DB]

Steel structures fail when extreme heat is present. The steel softens and can't maintain structural integrity.

I told my wife while the towers were burning that if they don't get the fires out soon the buildings would fail.

I was still shocked when it happened.

[Eastbound]

"Steel structures fail when extreme heat is present. The steel softens and can't maintain structural integrity."

Here is graphic evidence of that. Note the outward bowing of the steel column supports moments before collapse:

[definitelynotaliberal]

And he's a physics professor! Wouldn't you expect him to know a thing or two about the strength of materials, heat dynamics, etc.?