Originally Posted by sltr

here's why the building collapsed straight down-

First, the building is not solid; it is 95 percent air so it can implode onto itself.

Second, there is no lateral load- there was no force applied to sufficiently move the center of gravity such that it is not within the base footprint of the structure.

Third, given the near free-fall collapse, there was insufficient time for portions to attain significant lateral velocity.

To summarize all of these points, a 200,000+ t structure has too much inertia to fall in any direction other than straight down.