Millions of Americans in the country's heavily populated East Coast barricaded themselves in to brace up for Hurricane Sandy that will bring 11 feet waves that forecasters say will slam cities like New York, Boston and New Jersey.

Authorities declared a state of emergency from North Carolina to Connecticut as the superstorm made its way up the Atlantic on a collision course with two other weather systems, that could turn it into one of the most deadly storms to hit US.

The superstorm Sandy has plunged the final week of electioneering into chaos, with President Barack Obama and his Republican rival Mitt Romney cancelling and rescheduling their rallies in critical battleground states.

Warning that the megastorm could make landfall by late Monday or Tuesday morning, the forecasters said it could wreak havoc over 1,300 kms of eastern coastline to the Great Lakes.

Airlines cancelled more than 7,600 flights from Europe and Asia and began suspending train services across the north east. New York, which forecasters warned could bear the brunt of the superstorm and Philadelphia shut down their subways.

Schools, malls, superstores and even the stock exchanges put up closure notices. Boston, Washington and Baltimore also called off schools.

Sandy, a Category 1 hurricane packing winds of 120 kph has already taken 65 lives in Carribean, before it began travelling northwards. According to latest Met reports, the hurricane was reported just 684 kms south-east of New York City and moving at a speed of 23 kms an hour.

As rain and snow from the fringes of the storm began to fall on major US cities on the East Coast, tens of thousands of people were ordered out of their homes including 50,000 from Delaware alone, 30,000 in Atlantic city and Indian-dominated New Jersey.

Authorities warned that waves riding as high as 11 feet could swamp parts of lower Manhattan, flood subway tunnels and cripple electric and communication lines that are vital to New York financial centre.

Sandy has brought back memories of the hurricane Irene that had pounded the eastern seaboard last August, resulting in similar shutdowns, mass evacuations and power outages for millions.

New York Mayor Michael Bloomberg warned people in low-lying areas of Manhattan and Queens to get out.

"We have a plan to keep you and all New Yorkers safe. If you follow that plan, we'll get through this storm just fine. If you don't, people's lives are in danger. Not only yours, but the people who might be called to rescue you in an emergency," Bloomberg told a press conference.

"I can't stress enough that this is for your own safety, and that if you refuse to evacuate, you're not only putting yourself at risk, but also the first responders who will have to assist you in an emergency," he said.

President Obama also cautioned Americans not to treat the storm lightly.
"This is a serious and big storm," Obama said at headquarters of Federal Emergency Management Agency (FEMA) in Washington DC where he had gone to review the preparedness.

"And my first message is to all the people across the Eastern seaboard, Mid-Atlantic, going north, that you need to take this very seriously and follow the instructions of your state and local officials, because they are going to be providing you with the best advice in terms of how to deal with this storm over the coming days," Obama said.

In another unprecedented move, the UN headquarters here would remain closed today and possibly tomorrow due to the storm. All meetings at the UN were cancelled. The Nasdaq stock exchange also announced it would be closed today.

The city set up 76 evacuation shelters in public schools for people from low-lying areas of Coney Island, Manhattan Beach and other areas along the East River in Brooklyn in Manhattan.

The city's public schools, which cater to 1.1 million schoolchildren, were also ordered closed for Monday and the Coast Guard closed the New York Harbour.

The city's 468 subway stations, buses, rails, were also closed as officials advised people not to venture out. Utility companies warned that the hurricane could lead to power outages across several areas leaving people without electricity and heat for anywhere between 5-7 days.

Huge lines were seen outside grocery stores as water, food items, generators and batteries and other essential items flew off the shelves with residents stocking up for possible worse days after the storm has passed.

Forecasters said the water could top 8 feet from Ocean City, Maryland to the border between Connecticut and Rhode Island. They predicted the waves would rise to 6 feet on the south shore of Cape Cod. The storm was also expected to dump inches of snow in the region around Virginia.

New Jersey Governor Chris Christie also authorised closure of all State Offices for Monday, due to the impending impact of Hurricane Sandy and dangerous weather conditions.

Christie encouraged residents to comply with orders and guidance from their local emergency management and government officials in preparing for the storm and to avoid any unnecessary risks when the storm makes landfall.

Both Obama and Romney cancelled events in Virginia.

Romney also cancelled his New Hampshire trip, but would continue with his campaign in the battleground states of Ohio, Iowa and Wisconsin – which are away from the storm.

The Indian Embassy in Washington and the Indian Consulate in New York announced that their offices would be closed today due to storm.

The TriVisa offices, to which the Indian Embassy has outsourced its visa services, has also closed its offices in both Now York and Washington.

dc-gallery image