Storm Recovery Could Take Weeks as Millions Struggle
Christie, who called the shore damage "unthinkable," said a full recovery would take months, at least, and it would likely be a week or more before power is restored to everyone who lost it.
Sandy was the biggest storm to hit the region in generations when it crashed ashore with hurricane-force winds on Monday near the New Jersey gambling resort of Atlantic City, devastating the Jersey Shore tourist haven.
Flood waters lifted parked cars and deposited them on an otherwise deserted highway.
With the political campaign and partisanship on hold, President Barack Obama and Republican Christie toured New Jersey disaster areas on Wednesday.
"It's total devastation down there. There are boats in the street five blocks from the ocean," said Peter Sandomeno, an owner of the Broadway Court Motel in Point Pleasant Beach, N.J.
Christie, who has been a strong supporter of Republican presidential challenger Mitt Romney, praised Obama and the federal response to the storm.
Obama and Romney put campaigning on hold for a second day but Romney hit the trail again in Florida on Wednesday and Obama seemed likely to resume campaigning on Thursday for a final five-day sprint to Election Day.
(Read More: Obama to Visit Storm Victims as Campaign Resumes)
"This is the biggest challenge we've ever had," said George R. Gilmore, chairman of the Ocean County Board of Elections.
Obama faces political danger if the government fails to respond well, as was the case with predecessor George W. Bush's botched handling of Hurricane Katrina in 2005.
(Read More: October Surprise: Sandy Blows in on Final Days of Election)
Obama has a chance to show that his administration has learned the lessons of Katrina and that he can lead during a crisis.
"What the hurricane has done, not by intent, is give the president the opportunity to be presidential and to play that role very visibly," Sam Chandan, chief economist at Chandan Economics in New York told CNBC.
"Folks have been able to watch him on TV every evening, he's played that commander-in-chief role, so it may actually help them going into next week," Chandan said.
New York Under Water
Sandy brought a record storm surge of almost 14 feet (4.2 meters) to downtown Manhattan, well above the previous record of 10 feet (3 meters) during Hurricane Donna in 1960, the National Weather Service said.
New York City postponed its traditional Halloween parade, which had been set for Wednesday night in Greenwich Village. Christie also postpone Halloween trick-or-treating in New Jersey until Monday. (Read More: For New Jersey, Halloween Won't Come Until Monday)
Also postponed: the NBA's debut in Brooklyn in a season-opening contest Thursday night between the Nets and the New York Knicks at the new Barclays Center. But Bloomberg said Sunday's New York City Marathon would go on as planned.
The lower half of Manhattan went dark when surging seawater flooded a substation and as power utility Consolidated Edison shut down others pre-emptively. Some 250,000 customers lost power.
The parts of the city that are without power are seeing increased police patrols and other stepped-up security measures as they face the prospect of days without electricity. Officials said power might not be back until the weekend for hundreds of thousands of people.
There was no sign of looting or widespread crime, although about a dozen people were arrested in Coney Island and Queens on charges of trying to steal from shops, a pharmacy and the bank, where the entire front was missing.
Hospitals closed throughout the region, forcing patients to relocate and doctors to carry premature babies down more than a dozen flights of stairs at one New York City facility.
While some parts of the city went unscathed, neighborhoods along the East and Hudson rivers bordering Manhattan were underwater and expected to be without power for days, as were low-lying streets in Battery Park near Ground Zero, where the World Trade Center stood before the Sept. 11, 2001, attacks.
"I'm lucky to have gas; I can make hot water. But there is no heating and I'm all cold inside," said Thea Lucas, 87, who lives alone in Manhattan's Lower East Side.
While there were still only hints of the economic impact of the storm by Tuesday, AIR Worldwide estimated losses up to $15 billion — big numbers probably offset by reconstruction and repairs that will contribute to longer-term growth.
Andrew Economos, head of sovereign and institutional strategy for Asia at JP Morgan Asset Management, said the cost from the storm damage could be as high as $50 billion.
"We expect anywhere from $20 to $30 billion in losses, with upside of $50 billion," he told CNBC. "The good news is that the U.S. has proven time and time again that it can recover quickly given a fairly flexible economy and robust labor force."
Other analysts said any negative impact on the economy would be limited.
"Clearly the bounce back from these situations is relatively quick, people are insured and there is a reason to buy durables, so the negative impact on the economy from the storm will not be that significant," Uwe Parpart, managing director and head of research at Reorient Financial Markets, told CNBC Asia's "Cash Flow" on Wednesday.
Stephen Schwartz, chief economist for Asia at BBVA, agreed, adding: "We're still obviously watching for the damage and seeing how it unfolds. At this stage I think it's pretty clear it's going to shave off a bit of GDP growth in the fourth quarter, but we don think at this stage it really changes our outlook for the U.S. economy."
According to Frank Holmes, CEO at U.S. Global Investors fund management, the boost to the economy from reconstruction spending could be bigger than anticipated.
"There'll be a tremendous amount of spending and activity so there'll be a focused spending program to update and replenish a lot of old infrastructure. That's the positive part," he told CNBC.
Destruction Throughout Region
Cellphone service went silent in many states and some emergency call centers were affected.
Some cities like Washington, Philadelphia and Boston were mostly spared but the storm reached as far inland as Ohio and parts of West Virginia were buried under 3 feet (1 meter) of snow, a boon for ski resorts that was one of the storm's few bright spots.
(Read More: Sandy Knocks Out 25% Cell Towers Serving 10 States)
The western extreme of Sandy's wind field buffeted the Great Lakes region, according to Andrew Krein of the National Weather Service, generating wind gusts of up to 60 mph (96 kph) on the southern end of Lake Michigan and up to 35 mph (56 kph) in Chicago.
In Cleveland, buildings in the city's downtown area were evacuated due to flooding, police said.
Winds gusting to 50 mph (80 kph) brought down wires and knocked out power to homes and business.
City officials asked residents to stay inside and for downtown businesses to remained closed for the day.
Amid the devastation there was opportunity. Snowmakers at Snowshoe Mountain in the mountains of West Virginia had their equipment running at full speed on Tuesday, taking advantage of the cold temperatures to build the 24-30 inch (61-76 cm) base they need to open for skiing by Thanksgiving.