Here's the story of someone that was on the 84th flower of the south tower. Even though it was hit on the 78th-80th floors, he managed to get out of the building without much fuss.

This quote really tears me up:

"At about five minutes to nine there was an announcement by the Port Authority within our building. First the strobe lights flashed, as they did during their normal fire drills. The alarm system gave a little bit of a whoop whoop, you know, to alert you to an announcement about to be made. Then the very familiar voice, the one we heard all the time, came over the system and said, "Building Two is secure. There is no need to evacuate Building Two. If you are in the midst of evacuation, you may return to your office by using the re-entry doors on the re-entry floors and the elevators to return to your office. Repeat, Building Two is secure...."

I wonder how many people would have been saved if they had called for an evacuation? This should be investigated.