Deadly Sandy lashed the U.S. population-dense East Coast yesterday, killing at least 13 people in the United States and Canada, ?tearing down trees and power lines with hurricane-strength gusts, French news agency AFP reported.

The 13 deaths include 12 reported dead in New York, New Jersey, Maryland, Pennsylvania, West Virginia and North Carolina, and another Canadian woman killed by flying debris in Toronto.

At least five people were killed by the storm in New York state, including a 30-year-old man crushed by a fallen tree in the New York City borough of Queens, a spokesman for Governor Andrew Cuomo told U.S. media.

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 U.S. 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 truck 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 80 miles (130 kilometers) 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 U.S. Coast Guard also said it was?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 U.S. 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 yesterday.

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 travelers 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 in damage.