November 7, 1940: The Tacoma Narrows Bridge Collapses

Sixty-six years ago today, the middle section of the Tacoma Narrows Bridge collapsed during a windstorm, just four months after the bridge's completion. The mile-long suspension bridge carried traffic across the Tacoma Narrows of Puget Sound from Tacoma to Gig Harbor, Washington. Although preliminary construction plans had called for 25-ft. deep girders beneath the roadway, the final blueprints specified shallower, 8-ft. supports. Fortunately, the money saved by using less expensive materials did not lead to the loss of human life.

On November 7, 1940, wind-induced mechanical resonance led to the collapse of "Galloping Gertie", as the first Tacoma Narrows Bridge was affectionately known. Leonard Coatsworth, a driver stranded on the bridge, noticed that the windswept roadway began to sway as he drove past the bridge's towers. "Before I realized it, the tilt became so violent that I lost control of the car … I jammed on the brakes and got out, only to be thrown onto my face against the curb … Around me I could hear concrete cracking … The car itself began to slide from side to side of the roadway." After crawling on his hands and knees to safety, Coatsworth watched in horror as the bridge collapsed and his car plunged into the water below.

Ten years later, a redesigned version of the bridge - nicknamed "Sturdy Gertie" - opened to motorists. The redesigned structure included open trusses, stiffening struts, and openings in the roadway to let the wind through. Today, the Tacoma Narrows Bridge handles nearly 100,000 vehicles a day. Footage of the collapse of the original version is available on YouTube.