NEW YORK // Barack Obama, the US president, declared that a "major disaster" exists in New York and New Jersey states following the megastorm Sandy, freeing up federal aid for victims.
The declaration came after Sandy battered the US east coast, flooding lower Manhattan and leaving a half million people in New York City without power as the storm tearing down trees and power lines with hurricane-strength gusts.
At least 13 people have been killed in the United States and Canada.
Local officials in New York, New Jersey, Maryland, Pennsylvania, West Virginia and North Carolina reported 12 dead from the massive storm system, and Toronto police said a Canadian woman was killed by flying debris after the storm made landfall in New Jersey.
Much of New York was plunged into darkness as the superstorm overflowed over the city's historic waterfront, flooding the financial district and subway tunnels and cut power to hundreds of thousands of people.
The city had shut its mass transit system, schools, the stock exchange and Broadway and ordered hundreds of thousands of New Yorkers to leave home to get out of the way of the superstorm Sandy as it zeroed in on the US's largest city.
Residents spent much of the day trying to salvage normal routines, jogging and snapping pictures of the water while officials warned the worst of the storm had not hit.
By evening, a record 13-foot storm surge was threatening Manhattan's southern tip, howling winds had left a crane hanging from a high-rise, and utilities deliberately darkened part of downtown Manhattan to avoid storm damage.
"It's really a complete ghost town now," said Stephen Weisbrot, from a powerless 10th-floor apartment in lower Manhattan.
Water lapped over the seawall in Battery Park City, flooding rail yards, subway tracks, tunnels and roads. Rescue workers floated bright orange rafts down flooded downtown streets, while police officers rolled slowly down the street with loudspeakers telling people to go home.
"Now it's really turning into something," said Brian Damianakes, taking shelter in an ATM vestibule and watching a rubbish bin blow down the street before the storm surge.
Mayor Michael Bloomberg said late last night that the surge was expected to recede by midnight, after exceeding an original expectation of 11 feet.
We knew that this was going to be a very dangerous storm and the storm has met our expectations," he said. "This is a once-in-a-long-time storm."
A 30-year-old man was crushed by a fallen tree in the borough of Queens, a spokesman for Governor Andrew Cuomo told US media, one of five to be killed in New York state.
Also in Queens, a huge fire has destroyed at least 50 homes in a flooded neighbourhood.
More than 190 firefighters were trying to contain the blaze in the Breezy Point section and two people have suffered minor injuries, a fire department spokesman said.
The fire was reported around 11pm last night in an area flooded by the storm that began sweeping through the city earlier, officials said.
Elsewhere, two people were killed in Morris County, New Jersey when a tree fell on a vehicle, according to a local emergency management official.
Another two people were killed in Pennsylvania, one from a falling tree and another when a house collapsed, an emergency management official told AFP, without providing further details.
Elsewhere along the east coast, a US sailor on board a replica of the HMS Bounty was recovered from the sea and later died at hospital, and the captain was missing and feared dead after the tall ship went down off the Carolinas.
A woman in Maryland died after hydroplaning into a tree, officials said.
And in West Virginia, a 48-year-old woman was killed when her car collided with a cement lorry while driving through heavy snow caused by the storm, a local official said.
The National Hurricane Center downgraded Sandy to a post-tropical cyclone as it crashed into the US coast near Atlantic City, New Jersey but said it still packed hurricane-force winds of 130 kilometres per hour.
The storm also extended hundreds of miles in diameter, causing severe weather across a vast swath of states and in several major US cities.
Further north, in Toronto, Canada, a woman was killed when she was hit by flying debris, according to police.
In addition to the missing ship captain, the US Coast Guard also said it was also searching for a 40-year-old swimmer who went missing off the coast of Connecticut.
As a hurricane, Sandy killed at least 67 people — including a US national in Puerto Rico — as it swept through the Caribbean over the past few days but had been expected to morph into a far more powerful storm on today.
Authorities have warned the threat to life and property is "unprecedented" and ordered hundreds of thousands of residents from New England to North Carolina to evacuate their homes and seek shelter.
Falling trees dragged down power cables, plunging millions of homes into darkness as night fell, while storm warnings cut rail links and marooned tens of thousands of travellers at airports across the region.
Disaster estimating firm Eqecat forecast that the massive storm would affect more than 60 million Americans, a fifth of the population, and cause up to US$20 billion (Dh73.4bn) in damage.
Mr Obama spent yesterday at the White House overseeing the response to the disaster, taking a day off from the campaign trail a week before the November 6 presidential election.
His Republican challenger Mitt Romney also cancelled some campaign appearances in response to the storm.