Another famous example would be the collapse of the Tacoma Narrows Bridge in 1940, widely believed to have been caused by forced resonance. However, as per Wikipedia, the real cause of the collpase was aeroelastic flutter.

Video of bridge collapse : http://www.youtube.com/watch?v=xox9BVSu7Ok Wikipedia: http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge#cite_note...