New York...incredible image of The Twin Towers... during construction

Very good picture. You can see its core completely made out of steel which would never collapse straight and symmetrically at free fall speed down because of jet fuel

 If it fell over sideways, it would have killed way more people than what it did. I personally think it was a blessing that it fell the way it did.......even if it shouldn't have due to a plane hitting it.
The towers were made of three parts: the core structure which supported 60% of the weight, the outer walls which supported the remaining 40%, and the floor trusses which held them both together.