The Citigroup Center (once called Citicorp Center) at 601 Lexington Avenue in New York City was labeled Manhattan’s most “dangerous” building after a structural problem was found in 1978, soon after it was finished in 1977.
Designed by architect Hugh Stubbins and engineer William LeMessurier, the building had a special look with four stilts placed mid-wall to make room for St. Peter’s Lutheran Church at its base. This, along with a light steel frame and a tuned mass damper (a 400-ton concrete block to lessen swaying), made it creative but risky.
Sale
LEGO Architecture New York City 21028, Build It Yourself New York Skyline Model Kit for Adults and Kids...
- Architectural Essence - Capture the architectural essence of New York City with this magnificent LEGO set that brings together iconic buildings in an...
- Diverse Architecture - This wonderful model focuses on the amazing architectural diversity of one of the world's most dynamic cities, perfect for...
- Detailed Skyline Model - Build a detailed New York City Skyline model, featuring the miniature Statue of Liberty, Empire State Building, and a 4x32...
A Princeton student, Diane Hartley, and an NJIT student, Lee DeCarolis, each noticed issues with the building’s stability in strong winds, especially “quartering winds” (diagonal winds hitting the corners). Unlike most buildings, which are sturdiest at their corners, the Citigroup Center’s design made it weak against these winds.
Further checks showed that during construction, weaker bolted joints were used instead of the stronger welded joints LeMessurier had planned, making the structure less solid. Tests revealed that a 70 mph quartering wind could cause a collapse, especially if the tuned mass damper lost power (like during a storm blackout). Such winds were expected every 16 years without the damper, creating a huge danger.
LeMessurier and Citibank quickly fixed the problem, adding welded steel plates over the bolted joints in secret nighttime repairs from June to October 1978. The work was kept hush-hush, helped by a newspaper strike, and a plan to evacuate a 10-block area was made but never used, as Hurricane Ella turned away in September 1978. The story stayed secret until a 1995 New Yorker article by Joe Morgenstern shared it.
