In 1978, the Citicorp Center, a 59-story skyscraper in Manhattan, was built with a unique structural design. Instead of placing the main steel columns at the corners of the building, they were positioned at the center of each side to make space for St. Peter’s Church, which was located at the base of the tower. This design, along with an inverted chevron bracing system, allowed the building’s corners to extend outward, creating a distinctive cantilevered look. The 280-meter structure quickly became one of the tallest in the world, standing as a symbol of modern engineering. However, a critical change occurred during construction between 1975 and 1977. The contractor, seeking cost savings, replaced the welded joints in the steel framework with bolted ones. Welded joints are stronger and more rigid, while bolted joints are easier and cheaper to install but may be less stable under certain conditions. This decision was made without the knowledge of William LeMessurier, the structural engineer who had designed the building from a remote location. LeMessurier was not aware of the change until after construction had largely been completed. Later that year, a new calculation revealed that the load on these bolted joints increased by 160 percent under crosswinds—wind blowing sideways against the building—a scenario LeMessurier had not originally considered in his design. Concerned about the possibility of the building collapsing in strong winds, LeMessurier initiated a secret reinforcement effort. From August to October 1978, workers reinforced 200 critical connections at night while the building remained fully operational during the day. Experts monitored the work, ensuring the quality of the welds, maintaining a tuned mass damper (a device that helps reduce the building’s sway), and tracking weather conditions and strain gauges that measured the building's structural response. The city had prepared a plan to evacuate the Citicorp Center and nearby buildings in the event of severe winds, but this plan, along with the reinforcement work, was kept confidential. The story remained hidden until 1995, when journalist Joe Morgenstern from The New Yorker uncovered the details and published an article on May 29, 1995. The Citicorp Center incident became a key case study in engineering ethics, highlighting the importance of transparency, responsibility, and safety in construction. Today, the building, now known as 601 Lexington Avenue, still stands as a prominent feature of Manhattan’s skyline.