US authorities ordered coastal evacuations and airlines canceled transatlantic flights on Sunday as Hurricane Sandy bore down on the east coast after claiming 66 lives in the Caribbean.
Forecasters warned of catastrophic impacts from the mid-Atlantic to southern New England as the historic storm crashes ashore late Monday or early Tuesday, with New Jersey and New York City bracing for particularly dangerous conditions.
Nine days out from election day, the hurricane also threw the US presidential contest into disarray as Barack Obama and Republican challenger Mitt Romney cancelled events and prepared for the unexpected fallout.
Torrential rain and high waves battered South and North Carolina as the storm moved up the coast. The US meteorological service warned that New Jersey and New York could see record flooding because of the storm surge.
Sandy, which is packing hurricane force winds upwards of 75 miles per hour (120 kilometers per hour), has already claimed at least 66 lives in the Caribbean, most of them in Haiti, where 51 people were reported killed.
New York authorities issued an evacuation order for hundreds of thousands of people in low-lying coastal towns on Sandy's projected route. About 1,100 national guard troops were to be deployed in the towns and villages.
New York mayor Michael Bloomberg issued a mandatory evacuation order for 375,000 people in the city alone, including the threatened coastal zones of Coney Island and Staten Island.
The city was to open 72 shelters in schools and other buildings. It ordered subway, buses and commuter trains to close down from Sunday night. "This is a serious and dangerous storm," Bloomberg told a news conference.
At the city's Rockaway Beach, inhabitants started putting up sand bags on Saturday and many said they would brave out the storm as they did with Hurricane Irene last year.
Delaware and New Jersey also issued evacuation orders. Authorities ordered gambling to halt in Atlantic City from Sunday.
Airlines have cancelled hundreds of flights into airports along the US east coast.
Air France cancelled all flights into New York and Washington on Monday while US airlines have called off hundreds of domestic flights. New York airports were to stay open on Sunday but the airport authority warned passengers to expect disruption.
At 1500 GMT, Sandy was about 575 miles (930 kilometers) south of New York, the US National Hurricane Center said.
Though still far out at sea, the massive storm was spinning off high winds and seas for hundreds of miles around.
Television images from North Carolina's Outer Banks, a chain of low lying islands, showed wild surf and torrential rain.
Hurricane force winds were expected to batter a huge section of the US east coast from Virginia to Massachusetts.
Current projections show the storm making landfall early Tuesday on the Delaware coast, then bending north and inland as it merges with a cold front descending from Canada.
Weather experts say that the collision of Sandy with a cold front from the north could create a super-charged storm bringing floods, high winds and even heavy snow across a swath of eastern states and as far inland as Ohio.
Meteorologists have nicknamed the phenomenon a "Frankenstorm" because it is due to hit just before Halloween on October 31 and is composed of parts from different sources, as was Frankenstein's monster.
Governors declared states of emergency in Connecticut, Maryland, Massachusetts, New York, New Jersey, Pennsylvania, Virginia, the US capital Washington and parts of North Carolina.
"Sandy will be more like a large nor'easter on steroids," wrote Alex Sosnowski, a senior meteorologist for Accuweather.com, who said it could lead to billions of dollars in damage.