About building 7. Let us think logically, one column gave way and the whole building collapsed like in the link? Not a partial collapse, the facade? not a collapse starting at the column area and gradually collapsing the entire structure? The whole building comes down in it's foot print at the same time? I don't live in USA I don't care, but this is not the cause of the collapse, it is impossible. PS: no building is designed to collapse if one element fails, I am amazed how many people don't have basic common sense, You don't need an expert to understand that one column in the corner can't produce this kind of collapse.