http://georgewashington.blogspot.com/2007/11/shafted-on-911.html

Mechanical engineer Gordon Ross, in his July 2007 talk on the destruction of the Twin Towers, pointed out that:

“Those [core] columns which were situated adjacent to and accessible from inside the elevator shafts failed at an early stage of the collapse.

Those columns which were remote from the elevator shafts, and not accessible from the elevator shafts, survived the early stages of the collapse."*

Well, that's a coincidence. According to USA Today: "On Sept. 11, ACE Elevator of Palisades Park, N.J., had 80 elevator mechanics inside the World Trade Center".

And NIST itself says that, on 9/11, "Elevators 6A and 7A were out of service for modernization". (NIST NCSTAR 1-8, p.43).

In addition: