Hurricane David breezed by populous South Florida today, then headed up the seacoast, brushing the lavish mansions at Palm Beach and roaring inland at Cocoa Beach.

There, south of the space-launch complex at Cape Canaveral, the fierce winds unroofed apartments and scattered house trailers along the shore.

Behind David is tropical storm Frederic, east of Puerto Rico and heading northwest. Frederic was dropped from hurricane status after its winds diminished from 80 miles an hour to 65.

David's northward movement continued, and a hurricane watch was extended up the coasts of Georgia and South Carolina.

Traffic lights came crashing down, a 25-foot sailboat was hurled onto the shore at Lake Worth, and thousands of area residents were without power. But property damage was reported moderate south of Palm Beach.

Georgia officials urged evacuation of the barrier islands, and civil defense authorities there opened emergency operation centers in several counties. The Florida National Guard assisted in the evacuation of all persons living in low-lying coastal areas of Volusia, St. John's and Flagler counties, near where the storm was headed as it tracked along the coastline.

Officials at the National Hurricane Center here said the storm would continue northward and "be a threat, maybe to North Carolina," within the next 48 hours.

The South Florida death toll stood at five, largely the result of traffic accidents and heart attacks related to preparations for the storm, which at one point was the mightiest hurricane spawned in the Caribbean in the 20th century.

Hurricane David had leveled the tiny island of Dominica and killed more than 600 in the Dominican Republic before turning toward Florida and aiming its 105-mile-an-hour winds directly at Miami.

But at 5 a.m. today, abruptly and without meteorological explanation, David turned a bit to the north as it had twisted and turned before, veering off course from the coast of South Florida and the more than two million people living there.

The hurricane appeared to be careening from one millionaire's paradise to another, as it moved from Palm Beach north along the coast and bore down on Sea Island, Ga., playground of such wealthy, well-known Georgians as Jimmy Carter and Bert Lance.

"Due to weather conditions, the sand sculpture contest has been canceled," blared the public address system poolside at the Sea Island Beach Club as the winds picked up, the palms swayed and the seas churned.

As the local civil defense director urged a "voluntary" evacuation of Georgia's low-lying coastal areas, Sea Island guests jammed the checkout desk of the hacienda-style Cloister Hotel to break off Labor Day vacations early. Gray-haired patrons joked about life insurance policies and prepared wills, but there was anxiety in the air.

Earlier, federal and Miami officials had expressed deep concern over how a major hurricane would affect this Florida city, which has grown so fast so recently. Today, they expressed mixed opinions over how the public, 80 percent of whom were estimated never to have experienced a hurricane before, reacted to David.

Generally, the evacuation of tens of thousands of people from low-lying waterfront areas was carried off without a hitch. "We need to look at this thing and say, 'Hey, we had a good rehearsal, we had a good practice.'" said Monte McMullen, one of five Dade County civil defense coordinators. But he added, "I'm terribly concerned this will lull people about the next one . . . people saying, 'It's no problem,' or 'I've seen what it's like.'

"I'm worried now that they're going to say, 'You cried wolf.'"

Neil Frank, director of the National Hurricane Center here, said that decisions to evacuate were proper, given the information available for hurricane forecasters at the time. "Yeah, sure, I'm concerned." Frank said of the possibility that Miamians will think they have been through a major storm when in fact they experienced heavy and continuous rain and good stiff winds.

But he added that an evacuation order from Gov. Bob Graham for people in waterfront areas was not inconsistent. "It was very consistent with what I was saying" on the possible path of Hurricane David, the forecaster said.

Nevertheless, by late afternoon, a community that had seen fights and shoplifting in stores on Sunday was sending swimmers and surfers into the Atlantic off Miami Beach today.

The cloudy skies had opened and with them the Miami International Airport, which had been closed since Saturday night. It reopened shortly after noon today.

The early morning streets of Miami were absent of life, and a few uprooted trees and strewn debris made driving a rather testing experience. At one point, the telephone company had advised residents of south Florida not to phone in their pledges to the Jerry Lewis Labor Day Telethon, but by mid-day local telephone numbers for pledges appeared in bright lights across television screens.

At one point, about 25,000 Dade County homes were without electrical power as a result of the felling of 220 lines. In Broward County to the north, where Ft. Lauderdale is, 30,000 home were left without power because of damage to 160 wires.

All told, emergency shelters housed 18,000 people who fled the storm, and thousands of others simply moved inland from places like Key Biscayne and Miami Beach. Virtually all of them returned to their homes beginning at 9 a.m. today.

"We were really disappointed, we were disappointed. Nothing happened," said Edith Nemeth, a 73-year-old New Yorker after she returned to the front porch of her home, the Breakwater Hotel on Miami Beach's Ocean Drive.

"It was very unnecessary," she said of the evacuation. "Unnecessary. You know that else happened? I must tell you. We got into the bus" to return home "and the bus driver says, 'here, you have to get out'" -- blocks from the hotel. "Is that right?"

"I'm here 15 years in one room," said Bella Koppel, enjoying a porch chair at the Breakwater. While she said she didn't think the evacuation was necessary or convenient, she said, "I'll go wherever everybody else, goes" during the next hurricane. Koppel says she is 72; Nemeth asserts that she's past 80.

"I was very disappointed to leave here," said Sarah Gershtenbleet, 80, "and when we are told to leave I was disappointed, I wanted to see a hurricane first hand."

Koppel: "But what are you going to do?"

Bershtenbleet: "I've lived my life. I looked forward to seeing one for the first time. I doubt I'll ever the the opportunity again."

It was people like Gershtenbleet, Koppel and Nemeth who had caused much of the concern among state and federal officials about the reaction and evacuation of hundreds of thousands of people, many of them elderly retirees who have moved here in this decade of the Sun Belt.

Most of those interviewed, however, were more than a little put out about their relocation, which for many lasted less than 24 hours.

Efforts to obtain federal disaster assistance for South Florida are under way, and insurance claims writers were already in Miami before David, whose hurricane-force winds never came closer than 50 miles, was upon the coast.

Most of the area, however, appeared to have survived the storm intact, with the major losses the money being spent for the masking tape and plywood to protect windows and the bottled water, batteries, candles and radios that residents had purchased in anticipation of having to ride out the storm, possibly without electrical power and potable water. But they were prepartions for a disaster that really never came.

"We're not too sure what happened," said Frank at the hurricane center."When it was over Andros Island" in the Bahamas. "I said, 'My gosh, this thing's on its way.' But on the next report" from a reconnaissance plane "it turned it was significant only because it turned away from us," he said. If it had happened hundreds of miles out in the ocean, it wouldn't have been significant at all.