(William) LeMessurier, a highly respected structural engineer, worked on the design of the Citicorp building at 53rd Street and Lexington Avenue in Manhattan. When completed in 1977, the skyscraper became the seventh-tallest building in the world. Then, in June 1978 a New Jersey engineering student placed a call to LeMessurier. Assigned by his professor to write a paper about the Citicorp building, the student quizzed LeMessurier about the four columns that supported the skyscraper. The young man's professor thought that the structural engineer had made a mistake. Why had he placed the columns in the middle of each side of the building, rather than at the corners? LeMessurier explained that the professor was incorrect and described why circumstances required the columns to be placed in the middle of each side. Moreover, he told the student about the unusual system of wind braces that he had invented for this building. LeMessurier explained how the braces protected against the force of both perpendicular and quartering winds.
After the conversation, LeMessurier thought about lecturing his own students at Harvard's Graduate School of Design on the topic of his unusual system of wind braces. When he designed the columns, he had calculated whether the building could resist perpendicular winds, as required by the New York City Building Code. The code did not require any calculations pertaining to quartering winds (that is, those approaching the building diagonally), and the engineering literature generally did not concern itself with the impact of quartering winds on rectangular buildings. However, this engineering student had sparked LeMessurier's curiosity. He decided to run a series of calculations pertaining to quartering winds. The results showed more strain on the braces than he expected. The finding proved rather unsettling.
LeMessurier then recalled a discovery he had made just a few weeks earlier. During a meeting to analyze plans for two buildings in Pittsburgh, a contractor asked a question about the welded joints called for in the design of wind braces similar to those used on the Citicorp building. LeMessurier called his New York office to ask about the construction of the welded joints. His office explained that contractors actually had used bolted joints on the Citicorp building; Bethlehem Steel had objected to the welded joints. In that firm's opinion, the building did not require the extra strength required by the welded joints, and bolts saved a substantial amount of money. LeMessurier's New York office had agreed to the change, and they had informed him. The office's decision seemed to make sense at the time, because the engineers considered only the perpendicular winds, as required by the New York City Building Code.
With his new calculations, LeMessurier wondered whether the bolted joints could withstand the stress of high quartering winds. In our interview, LeMessurier told me that his instincts suggested that a serious problem might exist. He felt compelled to investigate further. He began to worry about a powerful storm triggering a catastrophic collapse of the building. He flew to Canada to speak with experts at the University of Western Ontario. He demanded a brutally honest assessment. They gave him one: the stress from quartering winds might exceed LeMessurier's latest calculations. He knew that he had a serious problem.
To his credit, LeMessurier took personal responsibility for the mistakes. He informed the building's architect and then flew to New York for a meeting with John Reed, then executive vice president of Citicorp (and later its Chairman and CEO). LeMessurier outlined the problem and then explained his strategy for repairing the building without alarming the public. Later, he met with Walter Wriston, Citicorp's Chairman. Repairs commenced soon after these meetings. LeMessurier recalled that both men treated him remarkably well throughout the process, and they did not try to punish him harshly for the errors. Over time, LeMessurier became an exalted figure in the field of structural engineering. People commended him for his willingness to be so forthcoming when he detected a potential flaw in his design.
-- Wharton