Rick Rescorla was the soldier used on the cover of the book “We Were Soldiers Once and Young”. He saved a lot of soldiers in Vietnam.
He later became head of security at Morgan Stanley in the twin towers. After the tuck bomb in the basement he got together with some ex-military friends soon after to figure out what the next attack would be like.
They all came up with the idea that it would be hijacking a large plane and crashing it into the buildings. So that’s what he planned for and trained the company employees to do. (Much to their complaints as he would practice dry runs and have them go down flights of stairs.)
He had them moving down the stairs right after the first plane hit, ignoring the shelter in place orders over the loud speakers.
IIRC everyone at Morgan Stanley evacuated in time. Rick was last seen heading up the stairs (after numerous other times up) to help others get out of the building.
After reading the article I see that 13 employees did die, but 2,700 lived!