[justa-hairyape]

The water comes ashore with velocity, and being heavy, it breaks things. One the structure's integrity is lost, the wind and surf together remove the debris.

There is a video on the MSM that was shot from someone inside a house that got Rita storm surge of up to at least 1/2 of their first story. Video shot inside large room with large open windows. Cameraman apparently standing on some furniture. The water looked downright dangerous. Lots of energy. Short powerful waves moving 500 to 1,000 gallons around in random directions.

[seeker41]

I saw that video on KHOU 11 here in Houston, scared me to death. I can't imagine being caught up in that surge.