Structural Integrity

When the (0:43) 601 Lexington / Citicorp Tower was completed in 1977, the 59-story skyscraper had a potentially fatal flaw that could have caused it to collapse in a severe storm. Once engineers realized the danger, they launched a secret emergency repair operation, welding through the night while evacuation plans and weather monitoring were quietly put in place. Subscribe to SiriusXM Podcasts+ to listen to new episodes of 99% Invisible ad-free and a whole week early. Start a free trial now on Apple Podcasts or by visiting siriusxm.com/podcastsplus . Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.