The New York skyscraper that almost fell over May 13 2014
You may have previously read about the Citicorp Center. Joe Morgenstern wrote about the Manhattan skyscraper in a classic New Yorker piece from 1995. The building was built incorrectly and might have blown over in a stiff wind if not for a timely intervention on the part of a mystery architecture student and the head structural engineer on the project.
Tells about designer William J. LeMessurier, who was structural consultant to the architect Hugh Stubbins, Jr. They set their 59-story tower on four massive nine-story-high stilts and used an unusual, chevron-shaped system of wind braces. LeMessurier had established the strength of those braces in perpendicular winds. Now, in the spirit of intellectual play, in his Harvard class, he wanted to see if they were just as strong in winds hitting from 45 degrees. He discovered the design flaw and during wind tunnel tests in Ontario learned the weakest joint was at the building's 30th floor.
The whole piece is here and well worth a read. Last month, the excellent 99% Invisible did a radio show about Citicorp Center and added a new bit of information to the story: the identity of the mystery student who prodded LeMessurier to think more deeply about the structural integrity of his building. (via @bdeskin, who apparently factchecked Morgenstern's piece back in the day)