I believe it was terrorists in hijacked planes that brought the WTC down (and crashed a plane into the Pentagon) and for many reasons ( it's not the first attack on the WTC, a truck with a few ton of explosives was planted in the basement of the WTC a few years ago, and many planes have been hijacked by terrorists in the past).
We all know that the American Government lie's, and that they (Bush Gov.) used 911 for their own purposes, political and otherwise.
But just because they grabbed the opportunity and ran with it does not mean they were responsible for it happening or indeed that they "let it happen"...
I just don't believe it would be possible to keep such a thing quiet...there's way to many greedy, selfish, sneaky, ambitious, money hungry, back stabbing, etc etc etc cunts in politics for it to stay quiet. I mean ffs, think of the money the person who knew something could aquire?...or bring down the Presidency etc...
I also have doubts re; the existence of Al Qaeda. The spin Doctors would have made this into the biggest possible threat they could have so as to justify the invasion of Iraq etc...I think it were terrorists, but not the organised world wide organisation the Bush Government and it's media propaganda would have us believe.