Prefatory note: this essay presents a theory, and I am not saying this is what happened. The scientific method is to raise theories, and then test them with the evidence to see if they are correct or incorrect.

I will leave it to the scientists, engineers and demolition experts to say whether this hypothesis is correct or incorrect. In fact, I am emailing this essay to some of the hundreds of highly-credible scientists, engineers and architects who question the government's version of 9/11. If the theory does not stand up in their minds, I will retract it.

Defenders of the official story about 9/11 have argued that controlled demolitions are always bottom-up, whereas the Twin Towers collapsed in a top-down fashion.

Initially, controlled demolitions are sometimes top-down. So the argument is not very persuasive.

Moreover, the destruction of the South Tower was, arguably, a conventional bottom-up demolition . . . with a twist.

Initially, the top 30 stories tip over as a unit: