A surprise, record-breaking snowstorm struck the Washington region and much of the eastern seaboard yesterday, shutting National Airport and causing treacherous road conditions and traffic havoc that officials said would have been far worse had federal workers not stayed home for the Veterans Day holiday.

The storm curtailed some Veterans Day events and turned a hoped-for holiday sales boom into a bust.

Thousands of commuters and travelers were stranded or otherwise inconvenienced by the storm, which resulted in four deaths, disrupted Amtrak and Metrobus service, caused a horrific 11-hour traffic jam along I-95 near the Woodrow Wilson Bridge, and forced schools to close early. {Details on school hours, Page C1.}

Metrorail, however, continued to run fairly smoothly with few delays throughout much of the day.

Red-faced forecasters, who had been predicting slight snow flurries and no accumulation, appeared to be as shocked as everyone else yesterday morning when freezing rain suddenly turned into a winterlike storm that eventually dumped 10 to 15 inches of snow on the metropolitan area by late afternoon. Freakish thunder accompanied the snow during much of the day.

"We didn't expect it to be this intense, this strong," said Bob Oszajca, a forecaster with the National Weather Service, who reported that the amount of snowfall rivaled some winter storms and set a record for this time of year.

Bob Hope, stranded in the nation's capital overnight after attending Veterans Day ceremonies at the Vietnam Veterans Memorial, was more to the point: "I thought I was in Moscow."

Parents of school-aged children hadn't expected the snow, either. They sent their children off to area classrooms, many of which were open despite the federal holiday, only to learn hours later that school authorities had revised their opening and closing times in the face of deteriorating weather conditions. By midnight, nearly 100 children were still stranded at their Prince George's County schools.

Washington has had earlier snowfalls, but nothing compared to yesterday's storm, according to the National Weather Service. The earliest snowfall of any significance, less than an inch, occurred Oct. 10, 1979, and the previous highest prewinter accumulation was of 6.5 inches on Nov. 6, 1953.

The snowfall, which had intensified during the day, began to ease by late afternoon and stopped altogether by early evening. Weather forecasters said temperatures would hover in the 30s during the night but were expected to climb into the low 50s by today, making snow removal efforts easier.

Snow removal authorities said they were generally prepared for the storm, despite the lack of warning, and most officials said they expected to have major streets cleared by this morning.

"Rain, shine, sleet or snow, the D.C. government is ready to go," boasted Mayor Marion Barry, whose jurisdiction has been the target of ridicule for past snow-removal efforts.

As of midnight -- four hours after an officially declared snow emergency took effect in the District -- the city's public works department and police had ticketed 640 vehicles and towed 129 along snow emergency routes.

The effort contrasted sharply with last winter, when cars were allowed to remain parked along major thoroughfares for days, snarling city plowing efforts.

By last night, major throughfares in the District appeared to be mostly clear of major accumulations of snow or ice. In Northeast Washington, snow routes along Michigan Avenue, Rhode Island Avenue and North Capitol Street appeared to be easily passable, although occasional cars were parked illegally. In Northwest, convoys of plows rumbled along Connecticut and Massachusetts avenues, and two towtrucks were seen removing illegally parked cars.

Capitol Hill, including the Union Station area of Massachusetts Avenue and portions of Constitution Avenue, appeared to be still suffering from significant accumulations of snow as late as 10 p.m., but officials said they expected to get to those main areas before the morning rush hour.

Downtown Washington streets also appeared to be easily passable, but ticket writers were out in force on major streets, in some cases brushing snow off license tags to write tickets on illegally parked cars.

Most of the city streets seemed to be nearly deserted, with only a few fast food businesses remaining open. Many pedestrians found walking in the cleared streets easier -- if not safer -- than walking on snow-covered walkways.

Earlier in the day, it it was clear that the bizarre pre-Thanksgiving storm caught many area highway crews by surprise. As road conditions deteriorated rapidly throughout the morning, there were numerous reports of fender-benders, several major accidents and three deaths on the roadways. And dozens of motorists complained that they encountered icy roads and bridges but saw little evidence of snowplows or sand trucks.

Freezing rain quickly formed a glaze on major bridges leading into the District.

Tractor-trailers driving yesterday afternoon on I-95 near the Wilson Bridge in Prince George's County became stranded in heavy snow, bringing about nine miles of bumper-to-bumper traffic to a halt for 11 hours in Maryland and Northern Virginia.

Maryland state police said last night that at least two stuck trailers forced all lanes of I-95 near the bridge to be closed from about noon until 11 p.m., when one north and one south lane were reopened.

Virginia state police said the tieup led to delays as far back as Springfield, which is about nine miles from the bridge. Police said they closed I-95 at the Springfield interchange about 10 p.m. Virginia state troopers patrolled the line of creeping cars for hours last night, and said they assisted dozens of motorists who had become ill or whose cars had broken down.

In addition, several major accidents involving tractor-trailers caused severe traffic tieups on parts of I-66 in Northern Virginia.

In one apparently weather-related traffic death, according to police, a Carroll County man was killed early yesterday when he fell 35 feet off the Patapsco River Bridge after leaving his disabled car on Rte. 70 in Howard County.

In another accident, 30-year-old Jose Natividade Sousa of Frederick, Md., died after his car collided head-on with another about 6 p.m. while crossing the Rte. 26 bridge over the Monocacy River.

Shortly before 5 p.m., a 61-year-old man was found unconscious after suffering an apparent heart attack while pulled to the side of I-95 near Springfield. Wendell Ward of Springfield was pronounced dead at Fairfax Hospital.

Alexandria police said the cold weather also may have been responsible for the death of a homeless man whose body was found yesterday morning under a truck in the 1000 block of Princess Street. Pending an autopsy, a police spokeswoman said the man appeared to have died from exposure.

Eight other deaths throughout the country were attributed to the weather. And in Shadwell, Va., east of Charlottesville, a Greyhound bus collided head-on with an automobile, injuring at least 13 persons, none critically, according to authorities.

The storm played no favorites in most sections of the East Coast as snow and sleet fell from southern New England to North Carolina. Snow and record low temperatures also were reported throughout the Midwest, and the cold air behind the East Coast storm was expected to bring freezing temperatures into the Gulf states by this morning.

The snowfall sent some providers of shelter for the homeless scrambling to find more space at a time when most shelters already are filled, according to advocates of the homeless.

"There are very few places that are able to squeeze in more people, and when the snow comes and nobody expects it, pandemonium sets in," said George Hicks, shelter director for the D.C. Coalition for the Homeless. "A lot of folks who sleep on grates, in abandoned cars and in buildings are not prepared for this. They just don't have the proper clothing."

In a peaceful protest shortly after midnight, homeless advocate Mitch Snyder and actor Martin Sheen were arrested at the Farragut West Metro station, where a fence was recently erected to prevent homeless people from sleeping there at night.

Despite the holiday, the snow conditions caused D.C., Maryland and Virginia police to enforce rush-hour parking restrictions and to declare an official snow emergency. Motorists were warned to stay off snow emergency routes unless they had snow tires or chains and to observe No Parking signs.

"Cars will be towed," said one D.C. Department of Public Works official.

"Make no mistake about it," said John E. Touchstone, director of the agency. "I was unhappy about the criticism we received last year. We didn't take an aggressive enough policy toward ticketing and towing . . . . We'll have to be tougher this year . . . . It's crucial that we be able to open those routes."

Statistics seemed to bear out Touchstone's remarks. During a two-hour rush hour, the District issued 291 tickets for illegal parking on just three major arteries: Wisconsin and Connecticut avenues in Northwest and Rhode Island Avenue in Northeast.

The number of snow emergency routes was reduced this year, eliminating many residential streets. But city officials warned that owners of cars found parked or abandoned along major arteries would be subject to fines of up to $50 in addition to a $50 towing fee.

Reports from the streets were mixed. Most motorists in Virginia, Maryland and the District reported long delays getting to and from work.

Bridges were icy, snow-covered and treacherous throughout the metropolitan area, but police said the situation would have been far worse if the storm had arrived on a normal workday. Still, those motorists who did venture from their homes had plenty of problems.

Police reported numerous minor accidents and advised motorists to avoid all but essential travel. Although traffic on the interstates and other major thoroughfares was moving -- albeit very slowly -- for most of the day, police said that snow removal efforts were hampered by stalled or abandoned vehicles.

At 11 a.m., "Montgomery County was reporting zero percent bare pavement," according to a spokesman for the Maryland highway administration.

In Virginia, a spokesman for the State Police said at midday that "traffic is just crawling" on major interstates. "It's at a standstill almost everywhere."

In the evening, some motorists who set out for home quickly thought better of it. Hotel managers reported a rush of late afternoon room bookings. Other motorists found the driving slow but possible, especially along major roads north of the city.

Most of the major commuter routes from suburban Maryland into the city had been plowed and salted by 4 p.m. But other roads, such as the Southwest Freeway, were still under heavy snow, and abandoned cars dotted the landscape.

Prince William County was particularly hard hit by the storm, though not everyone suffered.

"The towing business has been great," said Scott Albrite, manager of Scottie's Texaco in Manassas. "I've got six people waiting in the ditch right now. We've got four wreckers running and they are all out."

Police in Maryland and Virginia, which also invoked snow emergency driving and parking restrictions, said they had begun ticketing and towing abandoned vehicles to clear the way for snowplows and sand trucks.

For many area residents, the snowstorm was a good test of lessons learned last winter, when back-to-back blizzards played havoc with the region's transportation network and prompted a sweeping review of winter preparedness plans.

In Northern Virginia, state officials said that snow removal efforts were proceeding according to plan. Charles Perry, the district highway engineer, said maintenance crews had been on standby since Tuesday evening, and a full complement of snow removal equipment hit the streets between 4 and 5 a.m.

In Maryland, where snow removal is the shared responsibility of the state and county governments, officials gave varying accounts. According to a spokesman for the state highway administration, the state had mobilized 170 workers and 89 pieces of equipment in Montgomery and Prince George's counties.

But a Prince George's County official said the county was caught largely by surprise. "We were set up to pick up leaves," said Sylvester Helminiak, associate director for highway maintenance.

The storm knocked branches onto wires, causing temporary power outages to about 5,000 Virginia Power customers from Leesburg to Alexandria, according to a spokesman for the utility. By 11 p.m., fewer than 1,000 homes lacked electricity.

Some motorists had close calls; others avoided them. Juliette Hudson, 54, of Fairfax County was pulled to safety after her car overturned in a creek off icy Fort Hunt Road. Bob McHugh, also from Fairfax County and the owner of a new BMW, worried about even venturing out.

"I've been scared to death that somebody was going to hit it," said McHugh, who made a not-so-quick trip to pick up his daughter at school -- and then decided to park the car in an underground garage until the roads cleared.

Valerie Mark said nothing would deter her from shopping plans. She walked from Capitol Hill, where she lives, to Woodward and Lothrop downtown to check out designer party dresses.

Unlike tow truck companies, Jay Powell, owner of Dale City Auto Body Shop, wasn't swamped with calls yesterday. But he knows they are coming.

The storm, he said, "is good for business but bad for blood pressure."