ATLANTIC CITY, N.J. -- At least 13 U.S. deaths are being blamed on Superstorm Sandy, which has knocked out power to an estimated 5.2 million people across the East.
PHOTOS | Sandy along the East Coast
Sandy slammed into the New Jersey coastline with 80 mph winds Monday night and hurled an unprecedented 13-foot surge of seawater at New York City, flooding its tunnels, subway stations and the electrical system that powers Wall Street.
But for New York City, Sandy was not the days-long onslaught many had feared, and the wind and rain that sent water sloshing into Manhattan began dying down within hours. The full extent of the storm's damage across the region is unclear, and unlikely to be known until daybreak.
Heavy rain and further flooding remain major threats over the next couple of days as the storm makes its way into Pennsylvania and up into New York State. Near midnight, the center of the storm was just outside Philadelphia, and its winds were down to 75 mph, just barely hurricane strength.
NYC utility: Some outages could last up to a week
New York City's utility company says it could be anywhere from several days to a week before residents who lost power during the superstorm get their lights back.
Consolidated Edison says it's dealing with several different issues - downed overhead lines, a planned shutdown of underground networks and an unexpected explosion at a substation that darkened a large part of lower Manhattan.
Senior Vice President John Miksad says the planned outage should take three to four days to restore, while the explosion and the downed lines could take up to a week.
The company said 670,000 customers are without power in New York City and Westchester. A customer is an individual meter, so the number of actual people affected is likely higher.
Nation's oldest nuclear plant on alert
The nation's oldest nuclear power plant is on alert after waters from the colossal storm reached high levels.
Oyster Creek in Lacey Township, N.J., was already offline for regular maintenance before Sandy.
The Nuclear Regulatory Commission says an "unusual event" was declared around 7 p.m. when water reached a high level. The situation was upgraded less than two hours later to an "alert," the second-lowest in a four-tiered warning system.
Federal officials say all nuclear plants are still in safe condition. They say water levels near Oyster Creek, which is along the Atlantic Ocean, will likely recede within a few hours.
Oyster Creek went online in 1969 and provides 9 percent of New Jersey's electricity.
Amtrak cancels Tuesday service in Northeast
Amtrak says it has canceled all Tuesday service in the Northeast due to high winds and heavy rain from Hurricane Sandy.
The railroad said passenger service between Boston and Raleigh, N.C., and between the East Coast and Chicago, New Orleans and Florida will be suspended for the second day in a row.
Cancellations include Acela Express, Northeast Regional, Keystone and Shuttle service, among other trains. Passengers were urged to follow developments on Amtrak.com and Facebook and Twitter sites. No decision has yet been made on when service will be resumed.
Amtrak said passengers who have paid but who didn't travel because of the service disruption can receive a refund or a voucher for future travel.
Regulators: Financial system operating normally
Though U.S. stock trading was suspended Monday because of Hurricane Sandy, the parts of the financial system that stayed open functioned normally, the Treasury Department says.
Financial regulators found that systems involving payments, clearing and settlements of stock, bond and other market transactions worked without problems, in some cases through backup systems.
Treasury Secretary Timothy Geithner discussed the issues Monday with other members of the Financial Stability Oversight Council, which Geithner chairs. Among the matters they reviewed were the temporary closings of banks in areas affected by the storm.
The New York Stock Exchange has announced that stock trading will be closed again Tuesday.
Woman killed by falling sign in Toronto
Police in Toronto say a woman was killed by a falling sign as high winds from the approaching superstorm Sandy whip Canada's largest city.
A Toronto police spokesman said Monday that winds were about 40 mph (65 kph) in the area at the time the woman was hit by flying debris while walking along a street.
People across central and eastern Canada are bracing for the storm which is set to arrive early Tuesday with powerful winds and a deluge of rain.
Officials have warned residents in Ontario, Quebec and the Maritime provinces to prepare, though the East Coast of the United States will bear the brunt of the unusually large storm.
The storm is expected to continue to churn north and northwest, lashing parts of Canada.
Analysts say Sandy unlikely to damage US economy
Hurricane Sandy has already caused the cancelation of thousands of flights, stranding travers. Insurers are expecting to have to pay up to $5 billion. Retailers are expecting smaller sales.
But for the overall economy, damage from the storm is expected to be limited. And analysts say any economic growth that is lost to the storm in the short run will probably be restored after reconstruction begins.
Preliminary estimates are that the damage will range between $10 billion and $20 billion. That could top last year's Hurricane Irene, which cost $15.8 billion.
If so, Sandy would be among the 10 most costly hurricanes in U.S. history. But it would still be far below the worst -- Hurricane Katrina, which cost $108 billion.
Hurricanes, like other disasters, can cause big losses -- but also big spikes in economic activity afterward, as buildings are rebuilt or repaired. And Americans may spend more before the storm when they stock up on extra food, water and batteries.
Economic activity in October and November might slow if factory output declines, and if some workers are laid off temporarily and seek unemployment benefits. But the economy could strengthen in December as companies rebound.