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However, a critical calculation was overlooked. While designing the structure, LeMessurier assumed that the downward forces from gravity would exceed any lateral forces caused by wind. This led to the misconception that diagonal supports only needed to be built for compression, rather than for the tension they would encounter in reality.
The Undergraduate Investigation
The alarm was raised by an astute undergraduate student, Diane Hartley, who was studying the Citicorp Center for her thesis. After contacting LeMessurier’s firm with her findings, she discovered that the building could be at risk of failing in winds as low as 70 mph. This prompted a severe introspection for LeMessurier and a realization that swift action was required.