Hurricane Irene knocked out power to nearly 250,000 customers in North Carolina and Virginia today after making landfall after weakening overnight.
Irene, carrying winds of 140 km/h, is a Category One hurricane on the five-step Saffir-Simpson intensity scale.
It is expected to continue churning its way up the east coast through some of the most densely populated areas of the United States. Some 65 million people may be at risk from strong winds, heavy rains and battering coastal waves.
Hurricane warnings have been issued for North Carolina, Virginia, Washington DC. Maryland, Delaware, New York, Pennsylvania, New Jersey, coastal Connecticut and Rhode island, and Massachusetts. Emergencies were declared for North Carolina, Virginia, New Jersey, New York, Connecticut and Massachusetts.
Homeland Security Secretary Janet Napolitano warned yesterday of extensive power outages from the storm.
Operations at the two units of the Brunswick nuclear power station in Southport, North Carolina, were ramped down to 65 per cent of the total to make sure they could still run if the storm interrupted the electric grid operations.
New York City has ordered unprecedented evacuations and shutdowns of public transport.
A man died in North Carolina today when he was hit by a falling tree branch in Nash County. The storm's reach spread into coastal Virginia, Maryland and Delaware as it headed north.
President Barack Obama said the unusually large storm could be "extremely dangerous and costly" for a country that still recalls the destruction in 2005 from Hurricane Katrina, which swamped New Orleans, killed up to 1,800 people and caused $80 billion in damage.
Speaking from Martha's Vineyard last night before returning to Washington to deal with the crisis, Mr Obama said all indications point to the storm being a historic hurricane. "Don't wait. Don't delay," said Mr Obama, who decided to cut short his summer holiday by a day. "I cannot stress this highly enough: If you are in the projected path of this hurricane, you have to take precautions now."
Airlines cancelled nearly 7,000 flights over the weekend and all three major New York area airports were due to close to incoming flights this afternoon. The suspension affects John F Kennedy International, Newark Liberty
International, LaGuardia, Stewart International and Teterboro airports. It applies to domestic and international flights.
All Aer Lingus flights scheduled to operate to and from New York today and tomorrow have been cancelled. Flights to an from Boston tomorrow have also been cancelled.
Hundreds of thousands of residents and holidaymaker have fled from Irene's path. Supermarkets and hardware stores were inundated with people stocking up on food, water, torches, batteries, generators and other supplies.
Irene, the first hurricane of the 2011 Atlantic season, caused as much as $1.1 billion in insured losses in the Caribbean this week, catastrophe modelling company AIR Worldwide said, with more losses expected to come.
Defense Secretary Leon Panetta said the military stood ready to help in the response to Irene, with more than 100,000 National Guard forces available if needed in eastern states.
A quarter of a million New Yorkers were ordered to leave homes in low-lying areas, including the financial district surrounding Wall Street in Manhattan, as authorities prepared for flooding tomorrow.
A mandatory evacuation was ordered for residents in large areas of nearby Long Island, which juts into the Atlantic.
New York's mass transit system, which carries 8.5 million people on weekdays, is shutting down.
"We've never done a mandatory evacuation before and we wouldn't be doing it now if we didn't think this storm had the potential to be very serious," Mayor Michael Bloomberg said.
Irene will be the first hurricane to hit the US mainland since Ike pounded Texas in 2008.
In Washington, Irene forced the postponement of tomorrow's dedication ceremony for the new memorial honouring civil rights leader Martin Luther King Jr. Tens of thousands of people, including Mr Obama, had been expected to attend.
Flooding from Irene killed at least one person in Puerto Rico and two in Dominican Republic. The storm knocked out power in the Bahamian capital, Nassau, and blocked roads with trees.
Agencies