Gallopin' Gertie...

Gallopin' Gertie...  The Tacoma Narrows bridge failure in 1940 is famous amongst engineers, so much so that a photo of it almost always accompanies text on the consequences of bad engineering.  This collection of motion picture footage is the best I've ever seen of it. 

I had not previously known about the professor who risked his life in an attempt to save a dog (“Tubby”) in the only car abandoned on the bridge.  The professor got a bite on the hand for his trouble, with Tubby refusing to leave the car.  Tubby was the only casualty of the bridge's collapse...