AT least 14 people have died after storm Sandy slammed into the US east coast and hurled a record-breaking 13-foot surge of seawater at New York.
Sandy knocked out power to at least 5.7 million people and plunged large sections of Manhattan into darkness as water pressed into the island from three sides, flooding rail yards, subways, tunnels and roads.
Some of the 14 victims were killed by falling trees while police in Toronto said a woman was killed by a falling sign as high winds also hit Canada.
A backup generator failed at a major New York hospital, forcing it to move out more than 200 patients, including 20 babies from the neonatal intensive care unit.
"It's a challenging situation," NYU Medical Dean Robert Grossman said. "We drill all the time for this kind of thing. But this isn't a drill."
A fire has destroyed at least two dozen homes in a flooded neighbourhood in the New York City borough of Queens.
A fire department spokesman said more than 190 firefighters are at the blaze in the Breezy Point section. He says two people have suffered minor injuries.
Much of lower Manhattan was plunged into darkness by superstorm Sandy, a monstrous hybrid system that swept across a huge swath of the Eastern US.
Just before its centre reached land, Sandy was stripped of hurricane status, but the distinction was purely technical, based on its shape and internal temperature. Heavy rain and further flooding remain major threats over the next couple of days as the storm travels to Pennsylvania and New York State.
Near midnight, the centre of the storm was just outside Philadelphia, and its winds were down to 120 kph, just barely hurricane strength.
"We knew that this was going to be a very dangerous storm, and the storm has met our expectations," New York Mayor Michael Bloomberg said.
The National Hurricane Center announced at 8pm that Sandy had come ashore near Atlantic City. It smacked the boarded-up big cities of the Northeast corridor, with stinging rain and gusts of more than 135 kph.
The sea surged a record of nearly 13 feet at the foot of Manhattan, flooding the financial district and subway tunnels.
Deaths were reported in New Jersey, New York, Virginia, Pennsylvania and Connecticut.
Storm damage was projected at $10bn-$20bn (¤7.7bn- ¤15bn), meaning it could prove to be one of the costliest natural disasters in US history.
President Barack Obama and Mitt Romney suspended their campaigning with just over a week to go before Election Day.
At the White House, Obama made a direct appeal to those in harm's way: "Please listen to what your state and local officials are saying. When they tell you to evacuate, you need to evacuate. Don't delay, don't pause, don't question the instructions, because this is a powerful storm."
Mayor Bloomberg said late yesterday that the worst of the rain had passed for the city, and that the high tide was receding.
Still, authorities also feared the surge of seawater would damage the underground electrical and communications lines in Manhattan.
In an attempt to lessen damage from saltwater to the subway system and the electrical network, New York City's main utility cut power to about 6,500 customers in lower Manhattan.