9/11 Mysteries (Full Length, High Quality)

I'm not a believer in any of the conspiracy theories that have surfaced regarding 9/11 but I still found this 1.5 hour video on google interesting. The video claims that the buildings were demolished by planned explosions, not by the impact of the planes and the heat of the fires. Although I haven't watched the whole thing yet, the crux of their argument seems to be that the middle structure of the towers - the core - could not have been destroyed by the planes. The foremost report explaining the destruction did not explain how the middle core collapsed. Futhermore, witnesses on the day thought they heard explosions from the building. I'm still very skeptical on this as this conspiracy is far too big to be possible but have a watch and make up your own mind.