Lots of questions have been raised about 9/11: Why does it look like there is no plane at the crash site in Pennsylvania where flight United 93 came down? Why did a building called World Trade Centre Building 7 collapse even though it was never hit by an aircraft? And why was America so unprepared when terror attack warnings had been received? Through the internet and the media generally, allegations of complicity by the US government in the 9/11 attacks are intensifying. We found that simple requests, such as asking to see the plane wreckage of flight United 93 at Shanksville, or flight American Airlines 77 at the Pentagon, were refused after months of delay by the authorities. Yet if we had been able to film the wreckage from flight AA77 we would have had extremely strong evidence that a Boeing 757 hit the Pentagon. Trying to prove or disprove these alternative theories is not easy. Officials are loathe to engage, thinking that any response will only fan the flames of popular conspiracy theories, and yet no response seems to be worse still. Senator Bob Graham ... co-chaired the Congressional Inquiry into 9/11 which detailed the failure of the CIA and FBI to use intelligence it had received about Al Qaeda before the attacks. Senator Graham told us there was a "collaboration of efforts among agencies and the administration to keep information out of the public's hands."