Nagin said late Saturday that he's having his legal staff look into whether he can order a mandatory evacuation of the city, a step he's been hesitant to do because of potential liability on the part of the city for closing hotels and other businesses. In an alternate world, in which Nagin ordered (and implemented) an evacuation and Katrina swerved to the Florida Panhandle, you can see the lawsuits:
This unnecessary evacuation cost me everything to looters.
Our business is bankrupt because of his false orders.
Nagin lied, evacuees died.