Skyscraper had a 1-in-16 chance of collapse, Diane Hartley

On October 12, 1977, banking giant Citicorp opened the tallest new skyscraper in New York City since the early 1930s.

Were it not for two college students who helped uncover a grave flaw in the building’s engineering, Citicorp Center might have killed thousands of New Yorkers.

Citicorp Center still stands today, though it has since been renamed 601 Lexington.  

Unbeknownst to its owners, occupants and even architects, the brand-new $128-million skyscraper was far more vulnerable to wind than previously believed. 

If a storm knocked out the power to its stabilizing device, a strong enough gust could make it collapse — and, on average, winds powerful enough to topple the building would occur in New York every 16 years.

Hurricane Erin

Now, a comprehensive new book on the crisis, “The Great Miscalculation: The Race to Save New York City’s Citicorp Tower,” delves into the human stories behind the events of 1978

 — especially that of William LeMessurier, the structural engineer who blew the whistle on himself after being alerted to potential errors in his calculations.

The tower’s susceptibility to wind stemmed from its unusual design 

Diane Hartley, a young engineering student, was starting her final year of undergraduate studies at Princeton University 

when Citicorp Center opened. She decided to feature the tower in her thesis on the history and impact of tall buildings.

LeMessurier’s firm helpfully provided her with drawings, plans and figures. She visited the skyscraper to see its mass damper in action. But as Hartley modeled the tower’s response to wind loads, something didn’t add up.

“It never occurred to me that I had discovered something unusual,” said Hartley, who is now aged 69, in a Zoom call. “I was trying to figure out why I was wrong.”

 “And at that point, being behind and waiting to graduate, I footnoted that conversation and turned the thesis in.”

Hartley all but forgot about the interaction until the 1990s, when she saw a documentary about the tower saying that a mystery student had raised the alarm.

While some critics have questioned the secrecy with which repairs were made, LeMessurier was “almost universally commended for his disclosure and cooperation,” Greenburg writes. 

The tale of Citicorp Center has since become a morality tale of professional ethics, the author added: “It’s really become the seminal story when training engineers.”

CNN 15 augusti 2025

https://edition.cnn.com/2025/08/15/style/citicorp-center-new-york-skyscraper