(Part1)Jet fuel in open air burns at 500-600F that's cooler than a pizza oven! Google Jet Fuel or go to wikipedia.Steel melts at 2500-2700F.Forget about the towers for a moment and focus on WTC building 7.  The front facade was damaged in the collapse of the towers.  The structure sustained damage and absorbed allot of energy, yet remained standing.  Fires started from burning debris started on a few floors.  More than 6 hours later the 42 story tall WTC 7 fell straight down.