Specifically, NIST claims that the collapse of building 7 is "the first known instance of fire causing the total collapse of a tall building".
But then goes on to argue:
"The fires in WTC 7, which were uncontrolled but otherwise similar to fires experienced in other tall buildings, caused an extraordinary event"In fact, the fires in WTC 7 were orders of magnitude less than other high-rise fires, which did not produce collapses.
My parody from yesterday is not much sillier than NIST's real explanation.