That's part of what I find surpirsing I guess. I would have expected the wings to snap off like twigs and to have remained outside the building entirely....engines to rip off the pylons an keep going maybe. But the wings to smack into the building and break off outside.....that's what I would have thought. (and the vertical fin too.....)This is my biggest beef with a lot of the people. Airplanes, even BIG airplanes, and a 757 certainly qualifies as big, are still ultimately pretty fragile machines. Any airplane is built to with stand loads and stress only in certain ways, i.e. landing, flight, and pressurization, but any unusual load or stress outside of the designed/planned envelope or expected condition, even small ones are devastating to aircraft.
But I've been wrong before.