Originally Posted by indago

conspiriter wrote

The floors were designed to hold the tensile strength of the weight above. When the floors that were hit finally collapsed from the disintegration of the metal framework, and dropped onto the floors below, the floors were not designed to hold up under a sudden jolt, and collapsed; and so on, until all the floors were collapsed.

Retired National Security Advisor Richard Clark noted that a conspiracy that the buildings were sabotaged by government depends upon a couple of false premises:

1. That the government is competent

2. That they can keep a secret