THat is classic storm surge damage. If you go down along the Gulf coast you will find that most Condos have parking decks on the first floor and the condos start above that. Thats because the strom surge will take out the bottom floor bt leave the frame standing.
Good observation.
This is an excellent little collection of photos on Yahoo
http://news.yahoo.com/photos/ss/events/ts/080304tropicalweathe/im:/050829/ids_photos_ts/r427362715.jpg