46 people died because of little crack the size of a coin

On December 15th, 1967, during evening rush hour, ten days before Christmas, a bridge over the Ohio River collapsed in less than a minute, killing 46 people. Investigators eventually traced the entire disaster back to a single crack, about a tenth of an inch deep — hidden inside a steel joint, in a place no inspection method available at the time could have found it. This episode breaks down the Silver Bridge collapse: the innovative eyebar chain design with zero redundancy, the stress corrosion crack that grew invisibly for nearly 40 years, and how a single failed link brought down an entire suspension bridge in under a minute — and rewrote how bridges are inspected across the United States.