In a hundred years of experience with steel-frame buildings, none have ever suffered complete collapse from any causes other than controlled demolition and severe earthquakes. Yet few officials or engineers seemed surprised by the collapses of WTC 1, 2, and 7 into their footprints on September 11th.

Numerous articles have purported to "explain the collapses" of the Twin Towers, while the collapse of Building 7 doesn't even seem to warrant notice. Most of the explanations employ the "truss theory", in which the collapse sequence is initiated by falling of floors, eventually leading to column failure, while others contend column failure was the precipitating event. Regardless, the conclusion was foregone -- some chain of events caused the buildings to collapse of their own weight, the explosions, huge quantities of pulverized concrete, shredding of the steel frames, and other inconvenient facts aside.

The following are commented versions of published articles. Added commentary is in red. In the first article selected phrases of the original text are emphasized with boldface to illustrate the manipulative use of language in the ostensibly technical paper.

Why Did the World Trade Center Collapse?-Simple Analysis This was published on Sept. 13, 2001.
Why Did the World Trade Center Collapse? Science, Engineering, and Speculation This article by Thomas W. Eagar and Christopher Musso appeared in JOM.
The Collapse: An Engineer's Perspective This article is an interview of Dr. Thomas Eagar by NOVA and is on NOVA's website.
When the Twin Towers Fell This article in Scientific American is mainly notes from a panel of Boston area-based civil and structural engineers.

page last modified: 2005-03-08