you can see the missle flash being fired from the plane just before impact..and you can see it on the attack on the second tower. Thats how the planes managed to disapear into the building. They blew away enough of the support structure to absorb the plane.Still was not enough to bring the buildings down which just goes to show how wel they were built.So then, when they had the world media's full attention they initiated the demolition sequesnces.