Take a look at this guys and gals.
If you look at the satellite picture of New Orleans there is a red Katrina button on the top right of picture. If you switch between the tow you can see before and after.
http://local.google.com/maps?li=lmr&...hl=en&ie=UTF-8
The best way to see the effects is to follow the main roads.
Also this is quite interesting. Look at how the marina has been effected and the boats thrown to the bottom and bottom right of the picture. Then scroll down and look at the marina below.
http://local.google.com/maps?ll=30.0...9917&t=e&hl=en