If non-architects know the Citicorp Center—New York’s youngest landmark when designated at 38—they know it for its flaw. Shortly after its completion in 1978, a student called the office of its engineer, William J. LeMessurier, and asked about the four 24-foot-square, 100-foot-tall “super” columns, unusually positioned at the center of each of the skyscraper’s facades, that help to hold the building up.
In designing the building’s innovative structural system, LeMessurier had correctly calculated the strength of the wind hitting each face of the building straight on, but had failed to reckon with the extra strain of the “quartering” winds which hit the building’s cantilevered corners. In responding to the student’s questions, he realized he had made a mistake—one compounded by the substitution of bolted structural joints for welded ones, which are much stronger. By his calculations, a storm strong enough to topple the building hits the city every 55 years.
LeMessurier alerted Citicorp, who hired Leslie E. Robertson, engineer of the Twin Towers, to perform an ex post facto fix, “welding two-inch-thick steel plates over each of more than two hundred bolted joints,” a task which took two months. A press release issued at the time shows masterful use of the passive voice: “A review of the Citicorp Center’s designation specifications was recently made . . . [it] caused the engineers to recommend that certain of the connections in Citicorp Center’s wind bracing system be strengthened through additional welding . . . there is no danger.”
All this would have remained hidden by that bland language, were it not for some loose party talk. “The Fifth-Nine Story Crisis” was the title of Joe Morgenstern’s thrillingly written 1995 New Yorker story on the fix; a 2004 99% Invisible episode also told the tale, with the important update of the identification of the student—a woman, as it happened—named Diane Hartley. […]
