The 9/11 terrorist attack... What really happened?

[Mummelmann]

I dunno. The problem with most conspiracies is that they take it too far so no one takes it seriously. But there are certain oddities; the plane that ceased to exist on impact (as Metallicube mentioned), no surveillance at all from the Pentagon attack, finding intact passports with the culprits ID on them in the debris and the weirdest of them all, building 7 collapsing for no apparent reason at all.

I'm a very skeptical person by nature but quite a few things don't make much sense in this case.