NEW YORK, USA (AP) — The misery of superstorm Sandy's devastation grew yesterday as millions along the US east coast faced life without power or mass transit for days, and huge swaths of New York City remained eerily quiet. The US death toll climbed to at least 48, many of the victims killed by falling trees, and rescue work continued.

The storm that made landfall in New Jersey on Monday evening with hurricane force cut power to more than 8.2 million people across the East and put the presidential campaign on hold just one week before Election Day.

New York was among the hardest hit, with its financial heart closed for a second day. The storm caused the worst damage in the 108-year history of the city's subway system, and New York City Mayor Michael Bloomberg said it could be four or five days before the biggest US transit system was running again.

"This was a devastating storm, maybe the worst that we have ever experienced," Bloomberg said.

But the full extent of the damage in New Jersey was being revealed as morning arrived. Emergency crews fanned out to rescue hundreds.

A hoarse-voiced New Jersey Governor Chris Christie gave bleak news at a morning news conference: Seaside rail lines washed away. No safe place on the state's barrier islands for him to land. Parts of the coast still under water.

"It is beyond anything I thought I'd ever see," he said. "It is a devastating sight right now."

The death toll from Sandy in the US included several killed by falling trees. Sandy killed 18 people in New York City. It also killed 69 people in the Caribbean before making its way up the eastern seaboard.

Airlines cancelled more than 15,000 flights. New York City's three major airports remained closed.

Some bridges into the city reopened at midday, but most major tunnels and bridges remained closed, as were schools and Broadway theatres.

The storm sent a nearly 14-foot (4.27-metre) surge of seawater, a record, coursing over Lower Manhattan's seawalls and highways and into low-lying streets. The water inundated tunnels, subway stations and the electrical system that powers Wall Street and sent hospital patients and tourists scrambling for safety. Skyscrapers swayed and creaked in winds that partially toppled a crane 74 storeys above Midtown. A large tanker ship ran aground on the city's Staten Island.

Around midday, Sandy was about 120 miles (190 kilometres) east of Pittsburgh in Pennsylvania, pushing westward with winds of 45 mph (72 kph), and was expected to make a turn into New York State last night. Although weakening as it goes, the storm will continue to bring heavy rain and flooding, said Daniel Brown of the National Hurricane Centre in Miami.