Here's some film footage of the Tacoma Narrows Bridge collapse in Washington state, USA. Nicknamed "Galloping Gertie", it was a spectacular engineering failure. On the 7th of November 1940, winds of 42mph, sent the main span into torsional oscillations which increased in amplitude until the main span collapsed. The main bridge span exhibitied great flexibility in the 4 months it was opened to traffic before the collapse and this what gained its nickname "Galloping Gertie". The bridge collapse marked a turning point in engineering and aerodynamics that were not understood at the time. http://physics.kenyon.edu/coolphys/Frankli...ted/tacoma.html