WTC #7: Why did it fall?

I know I have brought this up before, and I also know that most people are sick of hearing about 9-11 especially since the media orgy of the five year anniversary, but I was farting around on YouTube.com and came across this video which hammers home some really good points. One of the reasons I posted this is because this video gives evidence that the official story apologists claim that Larry Silverstein's "pull it" comment was referring to a contingency of fire fighters is complete bullshit, considering that there were no fire fighters in it at the time.