Episode Details

When a 37-year-old listener asked why the Twin Towers fell, the honest answer turned out to be narrower and stranger than the popular story. The towers were the first structures outside the military and nuclear industries ever designed to resist jet impact — a voluntary act by the Port Authority, documented in a three-page white paper dated February 3, 1964. That paper concluded a Boeing 707 or DC-8 at 600 mph would cause only local damage. What it never addressed was fire. This episode walks through what the 1964 analysis did and did not consider, why chief engineer Leslie Robertson said the fuel load "was not considered in the design," how the 1968 New York City Building Code was actually less restrictive than the 1938 code it replaced, and why the towers withstood the impacts but not the multi-floor fires that followed. Key sources: • NIST — https://www.nist.gov/el/key-findings-nists-june-2004-progress-report-federal-building-and-fire-safety-investigation-world • NIST — https://www.nist.gov/news-events/news/2004/10/latest-findings-nist-world-trade-center-investigation-released • BBC Horizon — https://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/archive/leslie_robertson/index_textonly.shtml Episode 5932 — myweirdprompts.com/n/5932 (permanent short link: myweirdprompts.com/979498)