Okay, be honest. Did you even think you MIGHT see another plane hit the second tower that day? Even if your first thought was "terrorism" instead of "accident" (some people right here caught on to that a lot quicker than others that morning), DID IT occur to you that you might--MIGHT, mind you--see the same thing happen less than twenty minutes later? Did it cross your mind for even a nanosecond, before you actually saw it?
Well?
I mean, sure, after witnessing THAT, all sorts of possibilities occurred to me very quickly. I thought they were going to hit the Empire State building, the Chrysler Building, and Citicorp for sure (that building would tumble like a bowling pin, BTW), and then take out all the bridges and blow up the subways. And that was before the Pentagon was hit, so I don't think I'm lacking in the imagination department.
And it's just as applicable. That kind of damage to Tower 1 endangered Tower 2 (as evidenced by its eventual collapse), even if no other plane had been involved. It was absurd of the Port Authority (or anyone) to say, "Nothing to see here, return to your desks."
So now *you're* changing the subject from "roof door shouldn't have been locked/ criminally negligent homicide" to "building should have been evacuated". And you point to the collapse of the building LATER as evidence of how they should have behaved in Tower 2 BEFORE that happened. As has been discussed, the buildings were designed to take a considerable impact from a large airplane and still stand. Everyone who worked in the complex had probably heard that (everyone in the city has probably heard it at some point since 1974). Tons of explosives in the basement didn't bring them down in 1993 either. Security people are not engineers!--why would they suddenly assume the buildings might collapse?
The same situation was occurring at the Marriot hotel, right at the foot of the towers. Management advised the guests to stay inside. They didn't begin evacuating until the first tower collapsed right on top of them (partially collapsing the hotel itself; the next tower finished the job). I believe about 20 lives were lost, two of them hotel employees.
It's easy to say what someone should have done after the fact, but you can only go by what is occurring at the moment, and rely on your common sense, your instincts, and training, . Hotel managers usually aren't structural engineers either. At the moment it was happening, it might have seemed safest to keep everybody inside away from falling debris and bodies, and wait for the fire to go out and the coast to be clear. The greatest danger might have seemed, in the beginning, to be outside. Naturally that was proved wrong, but I don't know that I would have behaved any differently under the same circumstances.
Exactly why the point Uncle Sham made earlier in post #15 was valid. After '93, responsible people SHOULD have developed contingency plans so that such decisions would NOT be left in the hands of ignorant security guys and hotel employees once something happened.