It was the same in PA, Wal-Mart was the only place carrying stocks of American Flags.
Another biggie for me was the emergency call for supplies from the rescuers at Ground Zero in the days following 9/11. They badly needed boots, gloves, flashlights, batteries, bottled water, energy bars, etc. Wal-Mart was giving everyone a discount who came in buying stuff to donate to the searchers at the Trade Center rubble.
I've never been able to figure out what fuels this downright hatred of Walmart?