The Big Easy was decidedly uneasy Sunday as New Orleans prepared for its worst nightmare hurricane - a massive storm that could sit overhead for days, driving Lake Pontchartrain over its levees and submerging the city.

"We're just waiting for the trigger to be pulled," said Lt. Col. Ronnie Jones of the Louisiana State Police.Thousands didn't wait for Hurricane Georges to arrive. They fled, turning Interstates 10 and 55 into bumper-to-bumper processions. More than 1.5 million people were ordered or urged to leave New Orleans and coastal areas, and the city's streets were quiet and mostly empty.

The storm, with sustained wind of 110 mph, was expected to smash the Gulf Coast late Sunday or early Monday. Its course wobbled a bit during the day, giving hope that a slight deviation to the east could spare New Orleans the worst of the devastation.

Intermittent downpours started Saturday night along the Gulf Coast and continued Sunday night. Waves crossed beachfront roads in Mississippi, including four-lane U.S. 90. Twenty-five-foot waves clipped off fishing piers along Alabama's coast. High surf on top of a 5-foot storm surge threatened to undermine the foundations of beachfront homes on barrier islands along the Florida Panhandle. High winds knocked out power to at least 30,000 customers in the New Orleans area.

"I would be scared if I were in New Orleans right now," said Joerg Lehmann, 23, a German air force student at the Pensacola Naval Air Station. He was among the last people leaving Florida's Perdido Key.

More than 300 deaths had been blamed on the hurricane in the Caribbean.

Forecasters said up to 25 inches of rain could fall on New Orleans, coupled with a storm surge that could drive millions of gallons of water up the Mississippi River toward the city.

In a city that averages 6 feet below sea level and bordered by swamps, tidal lakes and the Mississippi - the results could be catastrophic.

Georges was the most serious storm to threaten New Orleans since 1969, when Camille slammed into the coast of Mississippi and Louisiana, causing flooding as far north as Virginia and West Virginia and killing 259 people.

"We're the best city in America," Mayor Marc Morial said. "But this may not have been the best place 300 years ago to place a city."

Tens of thousands flocked to the city's nine shelters, including the cavernous Louisiana Superdome and the sprawling Ernest Morial Convention Center. The city had capacity to shelter 100,000 of its 450,000 people, Morial said.

All flights in and out were canceled. More than 1.5 million people had been told to evacuate and police closed the interstates behind them. A 6 p.m. curfew was in place for New Orleans and surrounding areas.

Thousands more fled along the Gulf Coast in Mississippi, Alabama and Florida. Many schools were canceled at least through Tuesday, Mississippi's 11 coastal casinos were boarded up and harbors were closed to shipping.

As far north as Birmingham, Ala., about 260 miles from the coast, there were no vacancies left in motels along the major evacuation routes - interstates 10 and 65.

The normally raucous French Quarter in New Orleans was quiet, as most of the bars on Bourbon Street were closed and covered with plywood. Hotel workers rolled up awnings while stranded tourists strolled along the city's most famous street.

Some people stocked up to hunker down in their hotel rooms. Jim Porter of Ardmore, Okla., bought two bottles of water, three bags of potato chips and peanuts.

"I got gouged," said Porter, in New Orleans for a business meeting. "He didn't even ring it up on the cash register, just looked at it and said $20."

By 7 p.m. EDT, the hurricane's center was about 35 miles east of the mouth of the Mississippi River, or about 120 miles east-southeast of New Orleans. Wind blew around the eye at a sustained 110 mph, and forecasters said that might increase to 120 mph, making it a Category 3 storm.

Authorities said New Orleans' levees were built to withstand a Category 3 storm. A slow-moving one like Georges - stalled by high pressure to the north - was a different matter.