Mayor Ray Nagin instituted a dusk-to-dawn curfew to take effect at sunset and continue until the storm has passed. The curfew allows officials to arrest residents if they are not on their own property.
"Looting will not be tolerated," Nagin said. "Looters will go directly to jail. You will not get a pass this time."
Homeland Security Secretary Michael Chertoff was headed to the region Sunday and planned to stay through the storm.
"I'm well supported in terms of my ability to communicate back to the president and back to Washington, so I'm comfortable that I'm not going to lose touch," Chertoff said. "And so I'm not worried about my own safety."
With the storm speeding up and strengthening more quickly than expected on its way across the Caribbean and the Gulf of Mexico, some hospitals changed plans and decided to evacuate patients they had planned to keep on hand, Chertoff said.
"A number of the hospitals that originally planned to shelter in place have now decided they are going to actually try to evacuate their critically ill and medical needs patients," Chertoff told reporters before leaving for Louisiana. "As a consequence, we've had to increase the tempo of our air flights into New Orleans in order to make sure that we can accommodate the flow. We're going to be watching this very carefully today."
Long before Nagin's mandatory evacuation order took effect Sunday, residents were already streaming out of New Orleans and other communities along the Gulf Coast. On Bourbon Street, where the party seemingly never ends, only stragglers toting luggage were sporadically seen on the sidewalks.
Still, there were a few holdouts.
"You'd be a moron" not to be worried about the storm, Inez Douglas said at Johnny White's Sports Bar & Grill.
But while she was keeping an eye on the storm, she wasn't going anywhere.
Gustav crossed western Cuba on Saturday and has already killed more than 80 people in the Caribbean. It picked up speed upon reaching the gulf and was moving northwest at 17 mph with winds of 120 mph, according to the National Hurricane Center's 11 a.m. EDT update. Hurricane-force winds extended 50 miles from the storm's center.
Its center was about 325 miles southeast of the Mississippi River's mouth. The storm could bring a storm surge of up to 20 feet to the coast and rainfall totals of up to 15 inches.
A hurricane warning was in effect for over 500 miles of Gulf coast from Cameron, La., near the Texas border to the Alabama-Florida state line. Alabama Gov. Bob Riley issued a mandatory evacuation order for some coastal areas of Mobile and Baldwin counties.
In New Orleans, Nagin used stark language to urge residents to get out of the city, calling Gustav the "the mother of all storms."
"This is the real deal, not a test," Nagin said as he issued the evacuation order Saturday night. "For everyone thinking they can ride this storm out, I have news for you: that will be one of the biggest mistakes you can make in your life."
The mandatory evacuation of New Orleans is the first test of a revamped evacuation plan designed to eliminate the chaos, looting and death that followed Katrina.
Residents of suburban Jefferson Parish, swollen by residents who did not return to New Orleans after Katrina, were also ordered to leave in the first-ever mandatory evacuation of the entire parish.
The city will not offer emergency services to those who choose stay behind, Nagin said, and there will be no "last resort" shelter as there was during Katrina, when thousands suffered inside a squalid Superdome.
For residents with no other means of leaving the city, the last buses were going to leave at 3 p.m. Sunday.
Lines for the evacuation buses queuing up at the city's main transit center were much shorter Sunday than they'd been a day earlier.
"I'll be glad when it's over and I hope it doesn't mess up the city too bad," said Johnny Clanton, 59, waiting with a bag, hoping to catch up with a friend who also planned to leave the city.
President Bush and Vice President Dick Cheney will skip the Republican National Convention because of worries about Gustav. Bush had been scheduled to speak late Monday night in St. Paul, Minn.
And likely GOP presidential nominee John McCain and his running mate, Alaska Gov. Sarah Palin, were traveling to Mississippi.
Associated Press writers Peter Prengaman, Janet McConnaughey, Alan Sayre, Allen G. Breed, Mary Foster and Stacey Plaisance contributed to this report from New Orleans. Doug Simpson in Baton Rouge, La., Michael Kunzelman in Gulfport, Miss., and Peggy Harris in Little Rock also contributed.
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