The myth:

Segments of the US government were involved in co-ordinating the attack, providing the neo-conservatives with a high profile reason to begin the military 'democratization' of Muslim countries including Afghanistan and Iraq. To increase the spectacle, the towers were also demolished by explosives. These skyscrapers were designed to withstand fire on several floors, leading many to suspect foul play.

The truth:

The highly intense nature of the fires, primarily caused by aviation fuel and the length of time they were left to burn, have been proven to have caused the collapse of the towers.