On impact, the plane's fuel had exploded, sending a fireball down the side of the building and through the inside via hallways and stairwells. The fireball reached all the way to the 75th floor. One of the plane's engines, broken loose from the wreckage, shot through the building, tearing through several walls and finally out a south side window, finally coming to rest on the roof of a 12-story building across 33rd Street.
It was a smaller plane that was not travelling at 600 mph.
