Anon.
I think the walls of that building are so fortified that the general airframe turned to dust on impact, it has been documented - there is a video of a crash test airplane into a concrete wall.
Dust was all that remained.
(the holes were from engines would be my guess, or steel -not aluminum- parts)
Engineerfag, but not a forensic proof of shit. I did not witness that impact- I witnessed the second tower being hit by a plane with my naked eyes however.)