Superstorm Sandy slammed into the New Jersey coastline and hurled a record-breaking surge of seawater at New York City late on Monday, roaring ashore after washing away part of the Atlantic City boardwalk. At least 10 deaths are blamed on the storm so far.

Sandy knocked out power to at least 3.1 million people, and New York's main utility said large sections of Manhattan had been plunged into darkness by the storm, with 250,000 customers without power as water pressed into the island from three sides.

The US National Hurricane Centre said that Sandy had come ashore near Atlantic City. It smacked the boarded-up big cities of the Northeast corridor, from Washington and Baltimore to Philadelphia, New York and Boston, with stinging rain and gusts of more than 135 kph. The sea surged a record of nearly 4 meters at the foot of Manhattan, flooding the financial district and subway tunnels.

The 10 deaths were in New Jersey, New York, Maryland, Pennsylvania and Connecticut. Police in Toronto said a woman was killed by a falling sign as high winds closed in on Canada's largest city.