Rising abruptly and unmistakably from the Midtown Manhattan skyline, the slanted roof of Citigroup Center, formally known as 601 Lexington Avenue, has been an iconic part of the New York City skyline for decades. A great feat of engineering and modern architecture, Citigroup Center is unquestionably one of the city’s most unique and recognized skyscrapers. Few people, however, know the building’s hidden history, such as a potentially catastrophic engineering crisis realized shortly after the tower’s opening or its groundbreaking and trendsetting role in high-rise architecture. Here’s a quick look at the hidden history of Citigroup Center.
The building was commissioned in the early 1970s to serve as the headquarters of Citibank. Almost immediately, the building faced enormous engineering challenges. The site of the building, occupied by St. Peter’s Lutheran Church, was sold to the developers only on the condition that a new church be built on the same location with no direct connection to the new building. To accommodate this, the building’s structural engineers positioned the new tower itself on four massive columns, cantilevering over the new church and making the skyscraper appear as if it were built atop gigantic stilts.
The new building, rising 915 feet above the bustling New York City streetscape, opened in 1977 and featured an iconic and instantly recognizable slanted roof in the new Postmodern architectural style. The tower’s striking new architecture broke dramatically with the International Modernist style that had dominated the city for years, helping to usher in a new era of Postmodern architecture around the world in the years to come. Original plans for solar panels along the slanted rooftop were abandoned by developers, though the roof did contain a mass damper, the first New York City skyscraper to feature one.
Due to design changes during the construction of Citigroup Center, the building was structurally unsound upon opening. In 1978, engineering tests revealed that exceptionally strong winds to weaken and even topple the building, causing mass devastation. To correct the issue, Citibank quietly conducted structural repairs to the building over the course of three months without informing the public. Hurricane Ella threatened New York City while the repairs were only partially complete but later turned out to sea, allowing for enough time to strengthen the building. The repairs, completed totally in secret, were not revealed to the public until an article in The New Yorker broke the story in 1995.
Now structurally sound, the building – an architectural icon and engineering marvel – soon became an iconic fixture on New York City’s imitable skyline. The building was declared an official New York City Landmark in December 2016, signifying its importance to the worlds of modern engineering and architecture.