After days of dire warning, the densely populated Eastern Seaboard felt the first bite of a massive storm that snapped trees, ripped down power lines and flooded streets across the Washington region on Monday.

From North Carolina to New England, the coastal states were buttoned up as the big and uniquely formed storm system gained its first hold over land since killing almost 70 people in the Caribbean.

New York City was hit hard, with an unprecedented nine-foot storm surge conspiring with rivers already overflowing their banks. Streets flooded in Brooklyn and Lower Manhattan, runways at LaGuardia International Airport were underwater and a big construction crane snapped atop a skyscraper being built in Midtown. Four feet of water had flooded some city subways, raising fears they would cripple the system for days.

Late Monday, Mayor Michael Bloomberg said backup power had been lost at New York University hospital and the city was working to move people out, the Associated Press reported. The storm had killed at least one city resident, a man who died when a tree fell on his home in the Flushing section of Queens, according to the wire service.

With the storm expected to linger longer than most, virtually everything in and around Washington was to shut down for a second day on Tuesday. The federal workforce and public employees in the District, Maryland and Virginia were told to stay home again. Schools in the District and adjoining states closed. Metro and other transit agencies planned to remain out of service at least Tuesday morning.

No flights were expected Tuesday at the region’s three airports. Amtrak service north of the District was not expected to resume at least until Wednesday. Tens of thousands of homes lost power.

Gov. Martin O’Malley (D) said his state was “in the crosshairs” of a storm that “is going to . . . sit on Maryland and bear down on Maryland for a good 24 to 36 hours.”

The days of preparation afforded by the storm’s slow march toward the coast could not save the region from the myriad damage that proves that much of what man makes is no match for hurricane winds and floodwaters.

“This is one of, if not the, strongest storms on record in the Mid-Atlantic or Northeast,” said Jason Samenow of The Washington Post’s Capital Weather Gang. “In terms of a prolonged wind and rain event, this will be as strong as anything we’ve seen in several decades.”

The central core of Hurricane Sandy turned from the Atlantic into the shoreline near Atlantic City after nightfall Monday, but for all its almost 1,000-mile wingspan, Sandy was just the central element of a massive confluence of weather. Its tropical weather was expected to collide with the jet stream to the west and then be pinned from escape by a powerful nor’easter that will hold it in place over a multistate region where almost 60 million people live.

The bizarre combination of a late-season hurricane and a nor’easter, a storm type with some hurricane-like characteristics more common between October and April, was captured by Virginia Gov. Robert F. McDonnell (R).

“You’ve got flooding in southeast Virginia,” McDonnell said. “You’ve got a blizzard in western and southwest Virginia. And you’ve got high winds and heavy rain in Northern Virginia.”

For the second time in four months, lights flickered out in homes across the Washington region. The three major utilities fought a losing battle through the night to keep the power on, with regional outages reaching almost 160,000 by 9 p.m.

“We lost power about 7:50 p.m.” on Monday, said Craig Barnabee of Shady Side. “We last lost it during those straight-line winds in late June, and it was out for two days.”

Barnabee said he would start his generator Tuesday morning, but many people were likely to awake in darkness, unsure when their power might be restored.

Although advance help had been enlisted from as far as Texas, the region’s utilities were reluctant to promise when lights would come back on. It was expected to remain windy here until Wednesday as the storm moved slowly on a swing through New England.

“You have to wait until the wind subsides, then you hit it again as quickly as possible,” said Bob Hainey, spokesman for Pepco, which serves the District and much of the immediate Maryland suburbs. “The big word now is safety, safety, safety.”

Pepco had to recall its crews briefly during the height of the Monday night winds because it’s unsafe to use bucket-truck extensions in winds above 35 mph.

The National Weather Service warned that the Potomac River on Wednesday and Thursday would probably experience its worst flooding since a rapid snow melt after the blizzard of 1996.

Authorities in Virginia said the entire 37-square-mile Chincoteague Island was underwater up to three feet deep. The 3,500 islanders who had opted to remain on Chincoteague were told to stay in place because the causeway to the mainland was closed.

“It’s pretty rough,” police chief Edward Lewis said Monday night. “It’s blowing real hard. It’s raining sideways.”

Winds are picking up and gusts are bringing trees and power lines down, said Mayor Jack Tarr.

The wild ponies the island is known for had been moved to high ground before the storm.

McDonnell said he would apply for federal help to cover the cost for repairing public buildings, infrastructure and overtime for public safety officials.

Although the very worst of the storm was to have passed by daybreak Tuesday, the last of the wind and rain was expected to linger over the Washington area into Wednesday as the storm system pushed north over land into New England.

Even before Sandy reached shore, Atlantic City and its fabled boardwalk had been badly beaten by winds and were under floodwaters. The same was true up and down the coast line.

More than 100 feet of the fishing pier in Ocean City was snapped off by the angry surf. Those who ignored evacuation orders were told to stay put while the storm passed.

“You run from the water, and you hide from the wind,” said Joseph Theobald, the city’s director of emergency services.

Airlines had begun canceling flights up and down the East Coast over the weekend in advance of the storm, and it seemed unlikely local airports would return to normal until later in the week.

“When the airlines resume service is dependent upon weather conditions here in Washington, as well as in other cities on the East Coast,” said Jonathan Dean, spokesman for Baltimore-Washington International Marshall Airport. “It may take several days to accommodate the passengers that were disrupted by the canceled flights.”

Although Reagan National and Dulles International airports remained open, all flights were canceled Monday after the 9 a.m. departure of a flight from National to Atlanta and a 1:15 p.m. flight from Dulles to Tokyo.

At the Dulles Travelers Aid desk, volunteer Don Webster stayed busy all afternoon trying to help stranded passengers with hotel discounts and to book flights for Wednesday.   

“Because it is an act of God, the airlines are not paying for hotels,” he said as he helped three passengers. “Not much the airline can do about this.”

American Airlines spokesman Matt Miller said, “We’re hopeful that operations will resume in some cities on Wednesday, but it’s possible that the aftermath of the storm may force some additional delays and cancellations.”

Several hospitals said advance warnings about the storm allowed them to stock up on medication, food, linens and other supplies to last for the next 48 hours. Surgeries and procedures were taking place on schedule Monday, and several hospitals said they expect to remain open and operational Tuesday. But at least one — Washington Adventist Hospital in Takoma Park — canceled elective surgeries for Monday afternoon and Tuesday, a spokeswoman said.

Shelters in the District have been planning for several days for the storm, but there hasn’t been the expected influx of occupants yet.

“We’re ready for it,” said David Berns, the director of D.C.’s Department of Human Services. “Now we just have to get the cooperation of the citizens.”

District residents started trickling into city-run storm shelters after noon Monday, as rains continued soaking the city and winds started whipping down streets.

About a dozen folks sought shelter at Emery Recreation Center on Georgia Avenue NW, where most watched TV while others chatted or played board games.

Antonio Nelson, 27, decided to leave his apartment on nearby Nicholson Street when his lights started flickering. “I cut everything off and said, ‘I got to get out of here,’ ” he said. “I didn’t want to take any chance.”