The Column Failure Theory
Recurrent Theory of the Twin Tower Collapses
Suggestions of the column failure theory were apparent on the day of the attack, amidst the more frequent allusions to the core meltdown theory. Just two days later it was given the support of a technical paper, Why Did the World Trade Center Collapse?-Simple Analysis, written by Zdenek P. Bazant and Yong Zhou.
Although Bazant and Zhou describe their analysis as simplified and approximate, they express complete confidence that "The structural resistance is found to be an order of magnitude less than necessary for survival," and that the towers were "doomed" when the majority of columns of a single floor "lost their load carrying capacity". Simplified and approximate (and prompt) as it was, it seems to be the only published paper that purports to analyze the collapses quantitatively. Has no one else bothered to do a quantitative analysis of the greatest and most deadly structural failure in recorded history because Bazant and Zhou's simplified and approximate analysis is nonetheless comprehensively edifying and logically unassailable? Consider this review of their paper.
Analysis of the theory in light of the actual conditions show its assumptions to be unsupportable. It was soon overshadowed by the truss failure theory. By 2005, however, the column failure theory was restored to preeminence by an endorsement by NIST.