The Tacoma Narrows Bridge collapses in Washington State November 7, 1940.
(Bettmann/Contributor via Getty Images)
TACOMA, Wash. – Thursday marked 84 years since the Tacoma Narrows Bridge in Washington State collapsed during a windstorm four months after opening to the public.
On November 7, 1940, 42 mph winds blew through the area, causing the bridge span to bend and twist like a ribbon until it snapped and fell into the water below.
The bridge had been considered to be state of the art at the time, but a University of Washington professor had warned that holes should have been cut through the steel girders on the bridge, known as ‘Galloping Gertie,’ to let the wind pass through, according to FOX 13 in Seattle.
November 7 1940: Tacoma Narrows suspension bridge, in Puget Sound, Washington, vibrating violently just prior to its collapse due to hurricane winds causing a violent oscillating motion known as ‘flutter.’
(Keystone/Getty Images)
No one was killed or injured in the collapse, but a dog died after it was left in a car that was stuck in the middle of the bridge.
The official cause of the collapse was due to aeroelastic flutter. Most bridges use an open lattice beam truss to support the roadway which allows wind to pass through. But that wasn’t the case with the Tacoma Narrows Bridge, according to Bridge Masters Inc.
It was solid, which forced the air to pass above and below the bridge. That caused it to start bending and twisting in the wind until it finally collapsed.
Crews began taking down what remained of the bridge shortly after it had collapsed, but delays grew. The newly-constructed bridge opened to the public a few weeks before the 10th anniversary of the bridge’s collapse on October 14, 1950.