In this year long Batman story arc, Gotham City, suffering from the results of a magnitude 7.6 earthquake (depicted in the earlier Cataclysm storyline) is declared a No Man's Land by the US government. Laws are passed making it illegal to enter or leave the city after a particular date, and all known entrances and exits to the city are destroyed. The quarantine is enforced by the US Army and the JLA.
From the "Meet the Press" interview with Aaron Broussard, the President of Jefferson Parish:
Three quick examples. We had Wal-Mart deliver three trucks of water. FEMA turned them back. They said we didn’t need them. This was a week ago. FEMA, we had 1,000 gallons of diesel fuel on a Coast Guard vessel docked in my parish. When we got there with our trucks, FEMA says don’t give you the fuel. Yesterday — yesterday — FEMA comes in and cuts all of our emergency communication lines. They cut them without notice. Our sheriff, Harry Lee, goes back in, he reconnects the line. He posts armed guards and said no one is getting near these lines...
I know that Life Imitates Art, but why does it have to imitate such bad art?
It would be funny if it weren't so tragic.