A student's question exposed a wind flaw in the Citicorp Tower

In 1978, a Princeton engineering student named Diane Hartley called the offices of William LeMessurier, the structural engineer of the Citicorp Center tower in Manhattan, to ask about the building's unusual design: four columns at the center of each face rather than at the corners.

Hartley's question prompted LeMessurier to re-examine his calculations. He discovered a critical flaw: the building's tuned mass damper and bolted joints were not designed to withstand quartering winds (winds hitting the building at a 45-degree angle). A sufficiently strong storm could cause the building to collapse.

LeMessurier faced a dilemma: disclosing the flaw publicly could cause panic and a financial crisis for Citibank. He chose to inform Citibank and the city, and the repair was carried out secretly at night over several weeks, with welders reinforcing the bolted joints. The case illustrated how a student's question can expose a flaw that the engineer's own calculations missed, and how the ethics of disclosure can conflict with the economics of panic.