The major homeowners insurance companies are already lined up with a defensive line that the recent losses in that city were actually two separate events......ie Katrina and then the Flood.
Only some 40% of properties had flood insurance in addition to standard homeowner policies that only covers wind-related damage. The difference to these major insurers is measured in the billions of dollars.
The difference to hundreds of many thousands of NO residents is unthinkable.
There are going to be some heavy lawsuits coming from all of this, but not in time to help the average person like you and me if we were in their boat (bad pun, sorry :().