No, they were not. They had an inner skeleton made up of forty-seven steel columns that were heavily cross-braced. The only hollowed out parts of the towers were filled with elevator shafts.

There was a large restaurant on the TOP floor of the North Tower. If the building merely fell down into its own path, all the heavy-duty restaurant equipment should have been found in easily recognizable form in the rubble. Instead it all turned to powder. How?