There are sections of the city that were never flooded, had little storm damage, and have running water and generators for power.
Imagine you are in your house, with food, water, power. Imagine though that the neighborhoods that surround yours are all without power and are under water.
Now imagine what you would do if the police came to YOUR house and took your guns and forced you to leave.
The government has every right to refuse to rescue people who violate a "mandatory evacuation". But they shouldn't be allowed to remove you from your house without a warrant for your arrest. That's a CONSTITUTIONAL RIGHT.
Use it at night and make your house a target.