Quote Originally Posted by Bong30
i think it fell due to fire and

a version of this,

Pyroclastic flows are fluidized masses of rock fragments and gases that move rapidly in response to gravity. Pyroclastic flows can form in several different ways. They can form when an eruption column collapses, or as the result of gravitational collapse or explosion on a lava dome or lava flow (Francis, 1993 and Scott, 1989). These flows are more dense than pyroclastic surges and can contain as much as 80 % unconsolidated material. The flow is fluidized because it contains water and gas from the eruption, water vapor from melted snow and ice, and air from the flow overriding air as it moves downslope (Scott, 1989). The image on the right shows the formation of pyroclastic flows during a 1980 eruption of Mount St. Helens (photo courtesy of J.M. Vallance).

Ignimbrites and nuees ardentes are two types of pyroclastic flows. An ignimbite contains mostly vesiculated material whereas a nuee ardente contains denser material (Francis, 1993). Nuee ardente means glowing cloud and was named for the pyroclastic flows seen at Mount Pelee. These flows were often accompanied by a cloud of ash elutriated from the flow. When the incadescent ash particles are observed at night, the flow looks like a glowing cloud moving away from the volcano.

Pyroclastic flows can move very fast. Small pyroclastic flows can move as fast as 10 to 30 m/s while larger flows can move at rates of 200 m/s (Bryant, 1991). Nuees ardentes have been known to extend 50 kilometers from their source and Ignimbrites, because of the lighter weight material that they carry, can extend 200 km from their source (Bryant, 1991 and Scott, 1989). At Mount Pinatubo in the Philipines, pyroclastic flow deposits were 220 m thick in some valleys but averaged 30 to 50 m thick in others (Wolfe, 1992). Pyroclastic flows have been known to top ridges 1000 m high (Bryant, 1991). The image on the left shows a pyroclastic flow descending Fuego Volcano in Guatemala (photo by W.C. Buell IV, 1974).
Click here for a movie of a pyroclastic flow at Mount Pinatubo (movie courtesy of M.T. Dolan).


Pyroclastic flows can be very hot. In fact, pyroclastic flows from Mount Pelee had temperatures as high as 1075 degrees C (Bryant, 1991)! Some Pyroclastic flows from Pinatubo had temperatures of 750 degrees C and pyroclastic flows from Mount St. Helens had temperatures of 350 degrees C ( Bryant, 1991). Such high temperature flows can burn manmade structures, vegetation, and, for those unlikely enough to be caught by then, human skin


put a little jet fuel and some other flamables there is this thing called friction heat........you guys are dumb

just admit that you guys hate bush so much you will twist physics to fit your views
Yes i do hate GWbush for the damaged he has done to America,, so a fire made building 7 collaspe in a complete CD like way..hmmm you have to try harder then that....remember the burden of proof is on you the ones who beLIEve the government official conspriacy theory...