Above is a pretty famous and iconic piece of film–it has, for example, been chosen for preservation in the American Film Institute’s archive of historically and culturally significant films–but I’m surprised how few people have actually seen it. This is the real-life collapse of the Tacoma Narrows Bridge in Tacoma, Washington on November 7, 1940, one of the most dramatic engineering disasters ever caught on film.

The bridge was built beginning in 1938. Although some engineers working and studying the project warned that the girders chosen for the final design were too short, the Washington Toll Bridge Authority chose the cheaper design and went ahead with construction. From the day it opened the bridge was infamous for swaying in even moderate winds, and the vibration of the roadbed was amplified throughout the structure. On November 7, only a few months after the bridge opened, what you see in the dramatic video happened. No lives were lost thankfully, but the bridge was a total loss and the state of Washington had wasted $8 million, which was a fair chunk of change in 1940.

Due to World War II intervening, it was ten years before the replacement bridge was built–after extensive engineering studies were conducted to make sure it wouldn’t happen again. Today there are two Tacoma Narrows bridges, side by side. The second one opened in 2007.

Read more about this bizarre but fascinating disaster here.

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