Bombs and Explosions in the WTC Well Before the Collapses

Following up on this post, where I discussed two different men describing explosive events in the WTC basement well before the collapses of the buildings***, I remembered some other relevant stories.

First, is this Dick Eastman story:

Here is evidence supplied by the Head of Security of the WTC on network television indicating that the FBI floors (the 23rd and 24th floors) of the North Tower -- 60 floors below the crashbombing impact -- had been devestated and reduced to debris before the collapse of that tower, and that this same Head of Security himself dug through rubble that had pinned down two people to get those trapped persons out (they were saved, btw.) These floors were, thus bombed sometime between the ariel crashbombing of the building and its total collapse. Most likely it was bombed so that FBI agents working there would not be able or interested in removing critical files and evidence that the people behind the sabotage wanted destroyed.

Second is this fellow, who escaped from the South tower, and was going down the stairs when the plane hit:

My father thought I was still on the 73rd floor, and within 10 seconds of my call watched the second plane hit the South tower. He believed it was all over at that instant. I felt the impact of the explosion that I believed was at my feet. I heard the crashing glass around me as the building rocked. My hands began to shake and my knees buckled. I knew I could not stay where I was and I had to go lower. I made my way to the stairs, passing people along the way. I saw the horror and the fear in several faces as I went by them. I still believed the impact was at my feet and as I descended past floor 50 and floor 40 I was sure I was going to see disaster.

Were bombs planted on lower floors that went off when the plane hit?

This site covers people who witnessed bombs going off in the towers.

The bottom line seems to be that conventional bombs were set in the towers and were detonated when the planes hit-- no doubt using the plane impact as a distraction.

But how these conventional bombs fit in with the eventual total destruction of the towers is not clear. Were they the beginning of the controlled demolition? Or something different? Why would they have bombs go off early but then collapse the building with different bombs? Or did these early bombs help promote the collapse of the buildings by the official pancake model?

***It is highly unlikely that the desctruction they observed was due to the impact of the plane vibrating the basement region.