Um - the wings of a fully-laden airliner would have snapped off *forwards*, the inertia of the heavy fuel smashing them to pieces from the inside, then vapourising and exploding. There's a clear wide burn mark on the front of the building. Why would they create an impact hole? They would present a narrow front to the building, since the aircraft was nearly horizontal, having bounced *up* off the ground into the building. It was at an angle to it, though.
The plane hit between the first and second floors. The building didn't collapse with the impact (it's stronger than the plane, as I said) but with the fire, which will bring most things down eventually if allowed to burn.
The fuselage of an airliner is an air-filled tube of thin aluminium that will concertina and disintegrate in an head-on impact and, if exposed to fire, burn. The engines are solid, heavy lumps of dense metal which don't burn (pretty useless if they did) and at that speed have considerable energy and can smash through things. Hence why at least one of them ended up a good distance inside the building. Once the wall is penetrated, the fire can enter too, and working from the inside, eventually cause collapse. The evidence is precisely what you'd expect if you fly a fully-fueled airliner head-on into a steel reinforced masonry structure.
Broken windows - this photo shows broken windows across most of the frontage.
http://www.defenselink.mil/photos/Se...-8006R-002.jpg
There are also other photographs showing broken windows on the *inside* walls of the building.
Spot the errors in this article - another chap who's spent a lot of time plotting angles and things without actually considering how aircraft are constructed and how they behave in a crash. The bit about the engines 'exploding' is particularly funny.