Martin Filler on the collapse of the World Trade Center towers: “the towers' innovative external engineering that redistributed the walls' structural forces around the gaping holes after the attacks and kept the buildings standing long enough for a vast majority of their occupants to escape. Despite the ghastly death toll, the high survival rate for those in the towers below the impact points of the hijacked jets was no less than a miracle. Had the towers possessed conventional steel skeletons, they would have probably snapped and immediately fallen over, causing more catastrophic collateral damage than they did by crumpling onto their footprints.”
The book that Filler is reviewing, City in the Sky: The Rise and Fall of the World Trade Center by James Glanz and Eric Lipton may contradict the findings of American Ground by William Langewiesche (a book I've read, but in the form of the three magazine articles that were concatenated for the book, and a book which is recommended if you want to get an idea of the immensity of unbuilding the wreckage), at least about the reasons for the towers' collapse. Also worth checking out is an article by Lisa Kerr written in December 2001 about the Islamic influence on the buildings' architect and the buildings themselves.