Trade Center Collapse

Engineers: dislodged fireproofing brought down Trade Center towers

A new engineering report says if fireproofing material in the World Trade Center had been able to withstand the jetliner crashes, the towers likely would not have collapsed. The report comes from the National Institute of Standards and Technology, which is doing an exhaustive study of technical factors in the Nine-Eleven disaster. Shyam Sunder, NIST's main investigator, says the fireproofing on floors and supporting columns was knocked off by the impact and shaken off by the subsequent vibration. The agency suggests that builders explore improving the ways fireproofing is bonded to structural steel.