The biggest conspiracy theory : September 11 was fabricated

A number of urban myths, alternative hypotheses and conspiracy theories have been formulated to explain the events of September 11th:


The U.S., Israel or Iraq government orchestrated the attacks themselves.
The Twin Towers fell straight down, at close to free-fall speed. This is a similar characteristic of a controlled demolition. The dust cloud and its make up are considered un-characteristic of a gravity-driven collapse.
It is often pointed out that no steel building before or since the 9-11 attack has collapsed as the result of fire.
The rubble of the Twin Towers smoldered for weeks after the collapse. This claim is meant to point out that steel could only have smoldered as a result of pre-placed explosives.
Some consider photographic evidence of the plane lying on the grounds of the Pentagon to be ambiguous and unconvincing, citing a visual lack of burnt metal, human remains, passenger's luggage or seats.
The Pentagon was struck in a newly renovated, reinforced section. Some speculate this location, the west side of the complex, to be indicative of government involvement, noting it as an attempt to reduce casualties.
Flight 77 was able to fly in the direction of the DC and Pentagon area for approximately 40 minutes without interception. This is thought to be unusual given the Pentagon's close proximity to Andrews Air Force Base.
There are claims that anti-missile batteries at the Pentagon should have intercepted Flight 77.
The FBI confiscated a video, which may have captured the impact, from a nearby gas station attended by Jose Velasquez.