If the Sept. 11th attacks were an elaborate government plot, then how do conspiracy theorists explain United Airlines Flight 93, the plane that crashed in an abandoned strip mine near Shanksville, Penn.? Most people believe that passengers on board likely revolted, and the scuffle with the terrorists resulted in the crash. This theory is supported by cockpit recordings.
Conspiracy theorists don't think this story matches the evidence at the crash site, however. Much of the plane at the site was destroyed, and reports of sheet metal and papers found 6 miles (9.7 kilometers) away from the main crash site raise questions. Theorists don't think this could be the result of a normal plane crash, but rather argue that the plane must have been shot down by the government. Popular Mechanics' review of the details determines that debris did not land so far away as these reports indicate, and that all debris landed a reasonable distance from the crash considering the direction in which the wind and the plane were going [source: Popular Mechanics].
Some more outlandish theories claim the plane landed safely in Cleveland, where the passengers were scurried out and perhaps killed, before officials substituted another plane that was shot down in Shanksville. But others argue that identifying information of the plane and human remains prove Flight 93 crashed in Shanksville. They also say this conspiracy theory is mostly based on an early bogus news report (of which there were many that day) that Flight 93 landed in Cleveland.