I suggest everyone interested in this topic check out this vid, made by a highly regarded architect (watch all 13 parts when you get the chance, trust me its well worth it):
http://www.youtube.com/watch?v=b74naeawdCs
It's MUCH better and more informative than the more widely known Loose Change, and shows why it's scientifically IMPOSSIBLE for the towers to fall the way they did without explosives. Unlike Loose Change and many other 9/11 conspiracy documentaries that use speculation for the bulk of their content, this movie actually uses the principles of physics and engineering in disproving the official story. This is the video that officially sealed the deal for me in terms of believing the conspiracy.







