MOREHEAD CITY, North Carolina (Reuters) - Hurricane Irene charged up the U.S. eastern seaboard on Saturday as a weakening but dangerous storm that shut down New York City and threatened to inflict massive blackouts and flooding.

From the Carolinas to Maine, tens of millions of people were in the path of the giant 530-mile (830-km) wide storm that dumped more than 17 inches of rain on parts of coastal North Carolina after howling ashore at daybreak.

New York City ordered unprecedented evacuations and shut down its airports and subways, part of a huge public transit system that moves 8.5 million people a day on weekdays. Commuters were left to flag down yellow taxis and livery cabs that were patrolling largely deserted streets.

"We are trying to get to Boston and that is not going to happen. We're just stuck here," Rachel Karten said from the near-empty Port Authority Bus Terminal in New York. "We didn't think they would shut down everything."

Several million people were under evacuation orders on the U.S. East Coast.

With winds of 85 miles per hour (140 km per hour), Irene had weakened to a Category 1 hurricane on the five-step Saffir-Simpson intensity scale.

It could weaken to a tropical storm by the time it hits New England on Sunday, but the U.S. National Hurricane Center said that would make little difference in the impact from its damaging winds, flooding rains and dangerous storm surge.

"I would advise people not to focus that much on Category 1, 2 or 3 ... if you're in a hurricane, it's a big deal," U.S. Homeland Security Secretary Janet Napolitano told a conference call. "This remains a large and dangerous storm," she said.

New York Mayor Michael Bloomberg sternly told New Yorkers that Irene was still a life-threatening hurricane and urged them to heed evacuation orders.

"Staying behind is dangerous, staying behind is foolish and it's against the law," Bloomberg said at a media briefing at Coney Island in Brooklyn.

Some 370,000 city residents were ordered to leave their homes in low-lying areas, many of them in parts of the boroughs of Brooklyn and Queens and in downtown Manhattan, he said.

The hurricane center forecast a storm surge of up to 8 feet for Long Island and metropolitan New York when Irene passes on Sunday.

That would easily top the flood walls protecting the south end of Manhattan if it comes at high tide around 8 a.m. (noon GMT) on Sunday, hurricane expert Jeff Masters of private forecaster Weather Underground wrote in his blog.

Irene came ashore over North Carolina's Outer Banks near Cape Lookout around 7:30 a.m. EDT (1130 GMT), and then chugged up the coast on a north-northeast track. By 2 p.m. (1800 GMT), the center was 95 miles south of Norfolk, Virginia


When Irene hit the North Carolina coast at daybreak, winds howled through the power lines, rain fell in sheets and streets were flooded or littered with signs and tree branches. In the port city of Wilmington, the air was filled with the sound of pine trees cracking.

"You look outside and it's like nature is dancing for us," said Joe Toledo, who left his mobile home with his wife Cindy to take shelter in a hotel in Havelock, North Carolina.

A young boy was killed in Newport News, Virginia, when a tree crashed into his apartment, local media reported.

At least three people were killed in North Carolina -- one man hit by a falling tree branch and another washed away and feared drowned. Another man died of a heart attack while boarding up his house, Governor Bev Perdue said.

Nearly 650,000 people were without electricity in North Carolina and Virginia. Two hospitals were running on generators and two sewage treatment plants were without power. Perdue said there could be "a major hit" to tobacco crops, poultry and livestock.

"Fortunately, the force has not been the kind originally forecast," Perdue said.


Summer vacationers fled beach towns and resort islands. More than 1 million people left the New Jersey shore, leaving the glitzy Atlantic City casinos dark and empty.

Shoppers stripped the supermarkets and hardware stores of food, water, flashlights, batteries and generators.

"Our number of customers has tripled in the last day or two as people actually said 'Wow, this thing is going to happen,'" said Jack Gurnon, owner of a hardware store in Boston.

Airlines canceled nearly 7,000 flights over the weekend and all three New York area airports were to close to incoming flights on Saturday.

President Barack Obama cut his Martha's Vineyard vacation short by a day. In Washington, he joined a teleconference with emergency managers, who reported that Canadian utility crews had been called in to help restore power in Vermont, where every river in the state was expected to flood.

"It's going to be a long 72 hours," Obama said.

Irene was the first hurricane to hit the U.S. mainland since Ike pounded Texas in 2008. Emergency workers were mindful of the destruction wrought by Hurricane Katrina, which swamped New Orleans, killed up to 1,800 people and caused $80 billion in damage in 2005.

Defense Secretary Leon Panetta said the military stood ready to help, with 6,500 active duty personnel and more than 100,000 National Guard forces available if needed.

In Washington, Irene forced the postponement of a ceremony on Sunday to dedicate a new memorial to civil rights leader Martin Luther King Jr. Tens of thousands of people, including Obama, had been expected to attend.

The District of Columbia gave out 7,000 sandbags and residents in low-lying areas tried to shore up their homes against the anticipated flooding.

Irene swept through the Northeast Caribbean and the Bahamas as a Category 3 hurricane earlier in the week, bringing floods that killed one person in Puerto Rico and at least three in the Dominican Republic.

(Additional Reporting by Joe Rauch and Jim Brumm in Wilmington, N.C.; Pascal Fletcher in Miami; Basil Katz in New York; Susan Cornwell and John Crawley in Washington; and Michael Fitzpatrick in Long Branch, New Jersey; writing by Jane Sutton; Editing by Jackie Frank)

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