The BBC furnished this great pictorial on the locations of many of the damaged areas of New Orleans from Hurricane Katrina. As you can see, there is a lot of the area which is totally engulfed in water as a result of being below sea level. The size of the destruction is actually equal to the size of England - astonishing if this is factual...
As well the US has passed a list to the Swiss embassy in Bern, Switzerland of material it requires as it struggles to deal with the aftermath of Hurricane Katrina. The Swiss Foreign ministry said the list was quite long.
Along with the American Red Cross, the ICRC is trying to help those seeking information about relatives who may have been caught up in the disaster. They have a website which provides a list of people who are trying to find lost family members - http://www.familylinks.icrc.org/katrina
Ironically, this is the same type of list which was compiled during the Dec 2004 Sunami which hit Sri Lanka, Indonesia, Thailand and India. As I've seen, there are many blogs out there right now showing links to video feeds of the aftermath.