Rather interesting set of pictures from the Pensacola News Journal demonstrate what can happen to a bridge (bridges) when a 30 to 40 foot surge approaches. Apparently some trucker was on that Escambia Bay Bridge right in the heart of that hurricane. One who fear the wind itself would blow the truck off. From the pictures, it becomes obvious which way the waves came from and how (why) bridge sections failed.
http://tinyurl.com/5c43k