I hadn't thought of the houses being structurally unsound. That is a very good possibility!
I heard reports about some friends who live there. The wood that was submerged in water is splitting, after about three days in water. That is furniture and baseboards. The drywall that got wet has to be replaced. Plaster that gets wet kinda melts all over everything.
Anything that had floodwater in it is probably unsound and unsafe.