Other WTC Building "Collapses"

The North and the South Towers (a.k.a. WTC 1 and WTC 2 respectively) were not the only buildings to collapse suspiciously. This image (from The Blockbuster) shows the WTC complex after the collapses and the arrangement of the buildings before their destruction:

WTC 6 and WTC 7 both show signs of deliberate demolition. Here's a view of the area after the collapses (the perspective is 90 degrees clockwise from the first image):

WTC 6 is the (demolished) building with the hole in the middle of it at the bottom left corner of the plaza. WTC 7 once stood in the area immediately down and to the left of it.

WTC 7, although damaged by falling rubble, stood for about six hours on September 11th, then around 5 p.m. it suddenly collapsed. No official explanation for the collapse has been given. This building was completely flattened. Curiously, WTC 7 stood between the North Tower and WTC 6. If falling rubble flattened WTC 7 then why did it not flatten WTC 6?

Here's a close-up of WTC 6. According to the official story this building was destroyed because it was hit by rubble from the collapse of the North Tower. But if so then one would expect to see the remains of the building covered by rubble. Instead we see a huge crater. What could have caused this? It looks like what would result from a huge explosion in the basement of the building.