Due for testing by the US next year, the E-Bomb,-electro-magnetic pulse weapon burns out electrical components over a very wide area, thereby rendering the area electricity -less and with few vehicles still running- the principle was demonstrated in the film Small Soldiers. Such a weapon can also be fairly easily be constructed by a terrorist, or ascribed to a terrorist. This is a dispersed EM weapon.Tesla proposed a focussed EM device which would reduce a target to its component particles, over a long distance. Such would seem a reasonable answer to the collapse of the WTC towers.A centripetal vortex, sucking in the dust not releasing its energy until near the bottom of the disintegration in the form of billowing dust storms through the streets of Manhatten.