9/11 conspiracy theories

After shopping at my local food co-op tonight, I was approached by a young guy looking for signatures for a campaign to have an independent commission investigate 9/11. I asked, wasn't it already investigated? He said, yes, but there are still unanswered questions. I said, I don't have any unanswered questions. He said, what about how did building 7 collapse. I said that I was sure that had been answered at some point, and mentioned this article. My friend called out that he didn't believe in conspiracy theories. His partner was busy getting signature after signature. I didn't want to waste taxpayer money on another investigation because I think that the idea that the totally inept Bush administration could plan and carry out something that complex is ludicrous. I would only go so far to say that they may have suspected something was up, but purposely didn't do anything, so as to facilitate their wars. What do you think? Oh, and by the way, my dad was actually there that day but escaped.