>> the escalator trench acted as a chimney, made not of brick, but of highly flammable wood. at 7:45, a torrent of superheated gas rushed up the escalator, priming everything in its path to burn. >> the sudden movement of the fire up the escalator was called the flashover. it burst into the booking hall at the top. >> the hot gases and flames exploded into the ticket hall, feeding off years of thick paint on the walls and three tons of varnished wood on the escalator below. the cavernous room was a death trap. >> those people would have died extremely quickly. if there's anything, if there's any comfort there, is the comfort that they didn't suffer for very, very long at all. >> the government's board of inquiry accepted the new science of the trench effect and found it had caused the disaster. >> there was a general sense amongst people that rarely the underground should and could have prevented this. i mean, there were resignations,