"The buildings should have easily withstood the thermal stress caused by pools of burning jet fuel." - Kevin Ryan, former executive at Underwriters Laboratories (UL), the company that certified the steel used in the construction of the World Trade Center
According to Kevin Ryan, former executive at Underwriters Laboratories (UL), the company that certified the steel used in the construction of the World Trade Center,the steel components were certified to ASTM E119. The time temperature curves for this standard require the samples to be exposed to temperatures around 2000F for several hours.
And as we all agree, the steel applied met those specifications. Additionally, even un-fireproofed steel will not melt until reaching red-hot temperatures of nearly 3000F. Why anyone would imply that 2000F would melt the high-grade steel used in those buildings makes no sense at all.
Source: http://www.scoop.co.nz/stories/HL0411/S00177.htm