I found this on a posting.
Rescorla called in an old Army buddy, who oddly enough had converted to Moslem, to help him determine the weakness of the Twin Towers. Rescorla’s friend pointed to the exact pillar that, if correctly blown would drop one of the towers. It was in fact the pillar the Moslems tried to destroy. At the time of Rescorla’s death he was suffering from prostate cancer. If I remember correctly it was not of an aggressive nature.
I thought the unusual nature of the Towers was that they did not have a conventional internal skeleton, rather, it used the “tube frame structural system” that distributed the weight around the outside wall (59 columns on each side of the building and 47 columns in the center core) which allowed for an open floor plan. There were no individual columns that held the whole shooting match up.
It was the lateral trusses that held up the floors that weakened in the heat of the burning jet fuel and gave way in a rapid chain reaction. Nobody had calculated for the sustained heat of the burning fuel.