Amazing, This Was Not Oil or Gas Fired!
It was Jet Fuel which runs at a Much Higher Flame and Burn!
When a Fuel Such as This does its deed, the structure will debiliatate and degenereate.
It does not take a Friggen Rocket Scientest to figure this out!
The Towers Went Down and Killed many people and destructed other buildings in its path!
It did Not dropped straight down or there would not be Death and Destruction along with other Buildings except for those in Close Proximity!