But when the planes hit the twin towers on Sept. 11, 2001, they dislodged the fireproofing material protecting the steel columns and trusses that held the towers together. That proved to be the ...

He found that asbestos had peeled off the core columns up to the 78th floor ... warped, twisted steel. There's no spray-on [fireproofing] left." Victims' relatives seemed relieved that someone ...

Several theories outside of the NIST investigation have been put forward -- the floors collapsed pulling columns ... of fireproofing materials and connections used in steel structures, said ...

The company has acknowledged it needs to redo or fix the application of its fireproof coating on steel beams in its 36-story ... a newer fireproofing coating introduced last year.

With steel beams and columns concealed within masonry, concrete, or fireproofing, it can be easy to miss even advanced deterioration of vault structural framing. Until the surface material is ...