Construction began in September 1938. From the time the deck was built, it began to move vertically in windy conditions, so construction workers nicknamed the bridge "Galloping Gertie". The motion continued after the bridge opened to the public, despite several damping measures. The bridge's main span finally collapsed in 40-mile-per-hour (64 km/h) winds on the morning of November 7, 1940, as the deck oscillated in an alternating twisting motion that gradually increased in amplitude until the deck tore apart. The violent swaying and eventual collapse resulted in the death of a cocker spaniel named "Tubby", as well as inflicting injuries on people fleeing the disintegrating bridge or attempting to rescue the stranded dog.
Gif converted by Satcom Guru.
I think about that video every time I'm in traffic going over the bridge that replaced it. Not that I don't have faith in modern engineering (not so much in the upkeep of infrastructure in this country) but still, can't help but think about it as I feel it shake.
Fun fact about Washington (Puget sound) bridges, we have 4 of the 5 longest floating permanent bridges of which there are 20 in the world.