I agree. I don't think it is FEMA either, I think it is just that they have decided to close some stores, and have tried to pick an inconspicuous way to do it. But it got noticed.
Walmart to the rescue: Private Enterprises Response to Hurricane Katrina
I can't see a chain that can handle Katrina suddenly being out gunned by a plumbing problem. They would not inconvenience their customers, or allow competitors to get an advantage for six whole months if there was just a plumbing problem.