This video image shows the tip of American Airlines flight 77 (white area, just below horizon at right) before it hit the Pentagon. Photograph: AFP/Getty Images
If US defence department chiefs had hoped the conspiracy theories would stop, they might be disappointed.
The Pentagon released video footage this week from a static security camera which ostensibly shows the explosion as the hijacked American Airlines flight 77 crashes into the Pentagon on September 11 2001, killing 189 people.
The official story is that parts of the plane were recovered from the crash site and witnesses saw it hit the south-west side of the US military headquarters.
But conspiracy theorists have spawned numerous claims in the past about the Pentagon attack, for instance that the explosion was caused by a missile or a truck bomb, not a plane. Some even claim the US orchestrated the "missile attack" and wider 9/11 plot to advance the "war on terror" agenda. Not everyone agrees.
There is debate on the blogs about whether the new footage - secured after a freedom of information request by the legal rights group Judicial Watch - answers the theorists' questions or begs new ones. Slate calls the affair the "Pentagon caper".
The Hot Air blog and Captain's Quarters say that frames from the new video show a smoke trail belonging to the plane.
Watching the video, I can buy this. Maybe you can see a smoke trail.
But those who are suspicious argue that the footage does not clearly show a plane going into the building, only a fleeting, vague light shape, and then the explosion. One explanation for this is that the camera was low quality and the plane was moving at more than 500mph.
