The point about steel melting at 2750 degrees is misleading. Yes, steel melts around that temperature and yes, kerosene will not burn above about 1500 F, but the steel will loose structural integrity above about 1000 F.
The point about how fast the buildings fell is also misleading. The structure one each floor is designed to hold that floor, so once you get a few floors worth of equipment, furniture, etc., falling onto the one below it’s like dropping a bowling ball through a toothpick. It doesn’t slow it down much. Also, the main structure of the building is designed to primarily take the vertical load, so it comes apart pretty fast once you start twisting and bending the individual members.
Also, I’m sure the firefighters heard explosions. A 10 inch steel I-beam snapping will make an explosion like you wouldn’t believe.
A little internet research will make it obvious that dropping a building like that by explosive demolition would be a monumental effort and impossible to hide.
