So when people who were

[no_such_reality]

So when people who were onsite said

What people on site?

Plus, since when are 757’s built like bunker busters?

Simple physics time. kinetic Energy = 1/2 *m v^2

Cruising speed of a 757 is .8 Mach. or 270. Intentional dive and crash speed will be faster.

Weight of a empty 757 = 65000KG

Weight of fuel in aircraft = 11466 gallons at 6.84 lbs or 3.1 Kg or 35,000 Kg of fuel.

total craft weight 100,000 KG.

Energy density for combustion (explosion) of jet Fuel = 42.8 MJ/kg or 42,800,00 J/Kg

Kinetic Energy = 0.5 * 100,000 * 270 * 270 = 3,645,000,000 J (Joules)

Energy of unused fuel at 80% remaining = 0.8*35000* 42,800,000 = 1,218,077,275,484 J

Energy of a ton of TNT explosive = 4,184,000,000 Joules.

TNT equivalent of plane was a Ton of TNT.
TNT equivalent of remaining fuel was 290 Tons of TNT

An Exocet missle, used to turn a ship in the Falkland islands war into a floating slag has a warhead equivalent of 1/6th a Ton TNT. So the plane by itself slammed into the building like 6 Exocets.

For a massive ordinance penatrator bomb (bunker buster) weighs 13,600 KG ( 1/7th of the plane weight) it’s warhead is 2.7 tonnes, 1/100th of the energy in the plane’s fuel.