A vast snowstorm knocked life askew across a dozen states today, as electricity went out, flights were grounded and the most densely populated region in the nation slowed to a crawl.

Lumbering up the Ohio Valley, the slow-moving storm dumped snow in double digits in one state after the next, shuttering airports from Washington to Philadelphia and New York. Thousands of passengers were stranded. Amtrak canceled at least one-quarter of its trains in the Northeast, and the rest slogged through delays and snow-covered tracks.

The storm closed many local roads along its path, although not the Interstate 95 corridor, and left about 285,000 customers without electricity. In all, 28 deaths have been attributed to the storm, as it swept from Iowa and Nebraska to West Virginia and New Jersey.

Mountainous breakers, fed by a full-moon tide, slammed the white-snow beaches of Delaware; New Jersey; Long Island, N.Y.; and Massachusetts, and threatened some beach homes with ruin.

Along the snow-sleet-ice line in Kentucky, the Carolinas and Tennessee, officials reported flooding and trees down. Governors in at least eight states -- Kentucky, Pennsylvania, Delaware, Virginia, West Virginia, Maryland, New York and New Jersey -- declared states of emergency. The District declared an emergency, as well.

By nightfall, blizzard warnings extended into the northern reaches of New England, and Connecticut reported 17 inches of snow with more falling fast.

The storm could wreak havoc on already strained city and state budgets. In New Jersey, officials spoke of $15 million as the snow removal cost, and in Maryland and New York City, the bill could top $20 million.

Federal officials said that nonemergency government offices would remain closed Tuesday in the District, following the three-day weekend.

Still, many officials spoke of their relief that the storm fell across a holiday weekend. "It happened on Sunday with a holiday on Monday," said Edwin Truitt, director of emergency services in Delaware County. "If there is such a thing as an ideal snowstorm, this would resemble one."

New York Mayor Michael Bloomberg suggested that New Yorkers might consider riding the subway two or three stops to a favorite bistro or restaurant. But his emergency management officials noted later that subways were running sporadically, if at all, and that the wiser course might be to stay home.

The most impressive snowfalls came in the vertical lands of the central Appalachians, with 49 inches in western Maryland and 40 recorded in western Pennsylvania.

But it was in the coast's crowded cities that the snowstorm enforced its writ most noticeably. Eighteen to 25 inches of snow fell across Philadelphia, New York City and New Jersey.

In Philadelphia and New York, it was as though someone flipped the off switch. In New York, 1,300 plows rumbled through the storm, and the occasional Buick fishtailed down the street, a reminder that New Yorkers are at their best on foot and not behind the wheel of a car.

The appearance of the rare bus on the streets of Brooklyn set dozens of people to running through the snow. Judy Watson-Remy spent 21/2 hours traveling from her home in Fort Greene to pick up her 9-year-old son at a friend's house in Park Slope, a trip that normally takes 20 minutes. She finally boarded a bus packed with the shoving many.

"The bus driver was yelling at people to get out, and then the people yelled at him and said they'd take over the bus." She shrugged. "Y'know, it was your usual New York snow emergency crowd."

That said, New York was often shrouded and transformed today.

Cross-country skiers glided across Grand Army Plaza in Brooklyn, three grown men stood atop a crusted snowdrift and had a snowball fight. In Prospect Park, the wind registered like a hard slap on the face, but the sledding hills were jammed with children and adults, from middle-class Park Slopers to snowboarding Rastafarians to two Hasidic fathers sliding with their children on a toboggan.

Alexi Calisto prepared to push his 6-year-old, Freddy, down the hill on a garbage can lid. "The snow, the winter -- you don't get this in Mexico City," Calisto said. "I don't want this all the time, but for now it's great."

These have been edgy times in New York, with talk of Orange Alerts and bio-chem-whatever attacks. The snows drifting to shoulder height at corners seemed almost soothing. Waitresses in the Stargate Diner in Manhattan reported that customers chatted and left bigger tips.

And at James Cagney Park in Manhattan, Steven Portera, 47, photographed the snowy ridgelines of parked cars, and watched his children, ages 7 and 12, ride their sleds. The snowstorm, he noted, left the city quieter, its residents friendlier.

He has seen this before. "New Yorkers," he said, "are always nicer in a crisis."

In Brooklyn, in the Windsor Terrace neighborhood, the men at Farrell's Bar and Grill waxed poetic about the white hush that fell across their city, and the joy that accompanies a pell-mell hurtle down a fine sledding hill.

But carpenter Kevin Healy peered at 20 inches of snow piling up outside on Prospect Park West and had another thought: The storm of '03 is particularly pleasant viewed from inside an ancient Irish bar.

"My landlord shovels, and nobody's getting to work today," Healy said. "So I figure, I'll ride it out here."

And with that, he raised mug to lip.

Staff writer Christine Haughney contributed to this report.

Cars slowly make their way through whiteout conditions as a major snowstorm hits the Atlantic coast of Massachusetts along Revere Beach.