The mayor of New York has ordered the mandatory evacuation of 375,000 people ahead of Hurricane Sandy.
Michael Bloomberg said 72 evacuation centres had been set up around the city in schools and community centres.
Subway, bus and train services will be suspended from 7pm local time and hundreds of flights into the city's airports have been rerouted or cancelled.
"This is a serious and dangerous storm," Bloomberg said. "If you don't evacuate you are not just putting your own life in danger, you are also endangering the lives of the first responders who may have to come in and rescue you."
The hurricane is expected to start hitting the area on Monday.
All of the city's public schools have been closed, and the evacuation zone includes parts of Coney Island, Manhattan Beach and other areas along the east river in Brooklyn.
Stretches of Lower East Side, Staten Island and Manhattan are included.
People are boarding up their homes and businessesHurricane Sandy is heading north from the Caribbean - where it has killed 65 people - to threaten the eastern US with sheets of rain, high winds and heavy snow.
The majority of the deaths have happened in Haiti and the area around the capital Port-au-Prince, which holds most of the 370,000 Haitians who are still living in flimsy shelters as a result of the devastating 2010 earthquake.
Officials said 51 people have died there, though the number is expected to rise.
"This is a disaster of major proportions," Prime Minister Laurent Lamothe said.
The hurricane is expected to affect up to 60 million people in the US when it meets a winter storm and a cold front, plus high tides from a full moon, and experts said the rare hybrid storm that results will cause havoc over 800 miles (1,300km) from the East Coast to the Great Lakes.
Sandy was at Category one strength, packing 75 mph (120kph) winds, about 260 miles (418km) southeast of Cape Hatteras, North Carolina, and moving northeast at 10 mph (16kph) as of 8am (1200 GMT) on Sunday, according to the National Hurricane Centre in Miami. It was about 395 miles (635km) south of New York City.
The storm has also forced the presidential campaign to juggle schedules. Mitt Romney scrapped plans to campaign in Virginia on Sunday and switched his schedule for the day to Ohio.
First lady Michelle Obama cancelled an appearance in New Hampshire for Tuesday, and President Obama moved a planned departure for Florida to Sunday night from Monday to beat the storm. He also cancelled appearances in Northern Virginia on Monday and Colorado on Tuesday.
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