Excuse me, just one last thing that I forgot to correct.
In my first comment I said that no other building was seriously damaged. What I meant and should have said is that no other building had been brought down due to one of the towers falling into it. Of course the debris and the fire in the crumbled buildings damaged other neighboring buildings seriously so that they have been demolished afterwards. As I said, the amount of crumbled matter from a 415 m high building in a small area does affect nearby buildings.
Sorry for not having made this clear from the beginning.