How a Student's Question Saved This NYC Skyscraper

How a single phone call from a student helped uncover a flaw that nearly toppled Citicorp. Get an exclusive 15% discount on Saily data plans! Use code veritasium at checkout. Download Saily app or go to https://saily.com/veritasium If you’re looking for a molecular modeling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - https://ve42.co/SnatomsV Correction: From construction images of Citicorp, sharp-eyed viewers might see that the mid-V columns are still there. Those columns help prevent buckling of the diagonal and the weight of people on the floor above, but do not take the majority of the gravity load. So we left them out of our diagram to clearly explain the load paths. See page 70 of this source for more details - https://drive.google.com/file/d/1ODFo66-_V7Y9vKANbj53mQ0z20RZ2Uai/view Sign up to the Veritasium newsletter for weekly science updates - https://ve42.co/Newsletter ▀▀▀ 0:00 Why is the citicorp building on stilts? 4:44 How wind load works 7:49 Tuned Mass Dampers 11:17 The Anonymous Student 14:00 Quartering Winds 18:38 What were the odds of collapse? 20:31 How was the citicorp building fixed? 25:40 Hurricane Ella 27:00 TMDs Take Over The World 28:36 Conspiracies and Cover Ups ▀▀▀ A big thank you for the incredible people without whom we couldn't have done this! 🖤 To Michael Greenburg, author of The Great Miscalculation, for his insights that really brought the story and its context to life. He gave us a pre-copy of his upcoming book, and it is fantastic: https://ve42.co/Miscalc To Eric Hines for all his help with the technical details, fact-checking, and making sure we got the engineering right. To Michael J. Vardaro for helping us uncover the details of the story and the resources he provided. To Brock Hedegaard for helping us dive deep into the Citicorp structural analysis. Learn the fundamentals of structural analysis on his brilliant channel, @StructuresProfH, and see here for his analysis of the citicorp