Its arrival, eight days before the U.S. presidential election, forced President Barack Obama and his Republican challenger, Mitt Romney, to alter or cancel several campaign stops. Obama flew back to Washington from Florida, telling reporters at the White House that assets were in place for an effective response to the storm.
"The most important message I have for the public right now is please listen to what your state and local officials are saying," Obama said. "When they tell you to evacuate, you need to evacuate."
Water pours over cars in Manhattan as superstorm Sandy flooded large parts of the island on Monday, October 29. 2012. The storm surge from Sandy set records in lower Manhattan, where flooded substations caused a widespread power outage
Taxis drive down a New York street where the power was out late Monday, October 29.
A firefighter speaks to a colleague while surveying damage caused by Sandy on Monday in New York.
Flooded cars line the streets of New York's financial district Monday night.
Though no longer a hurricane, "post-tropical" superstorm Sandy packed a hurricane-sized punch as it slammed into the Jersey Shore on Monday, killing at least 11 people from West Virginia to North Carolina and Connecticut.
Sandy whipped torrents of water over the streets of Atlantic City, stretching for blocks inland and ripping up part of the vacation spot's fabled boardwalk. The storm surge set records in Lower Manhattan, where flooded substations caused a widespread power outage. It swamped beachfronts on both sides of Long Island Sound and delivered hurricane-force winds from Virginia to Cape Cod as it came ashore.
Sandy's wrath also prompted the evacuation of about 200 patients at NYU Langone Medical Center.
"We are having intermittent telephone access issues, and for this reason the receiving hospital will notify the families of their arrival," spokeswoman Lisa Greiner said.
In addition, the basement of New York's Bellevue Hospital Center flooded, and the hospital was running off of emergency backup power. Ian Michaels of the Office of Emergency Management said the main priority is to help secure additional power and obtain additional fuel and pumps for the hospital.
The storm hit near Atlantic City about 8 p.m. ET, the National Hurricane Center reported. It packed 80-mph winds at landfall, down from the 90 mph clocked earlier Monday.
A truck drives by a flooded gas station in the Gowanus section of Brooklyn on Monday.
A flooded street is seen at nightfall during the storm on Monday in Atlantic City, New Jersey.
Firefighters evaluate an apartment building in New York that had the front wall collapse during the storm on Monday.
Much of FDR Drive in New York was flooded by Sandy.
Heavy rains fall in Manhattan on Monday.
People walk through water on the beach near high tide Monday as Sandy approaches Atlantic City.
Two men run down Foster Avenue while dodging high winds and waves from the storm on Monday in Marshfield, Massachusetts.
The storm had already knocked down power lines and tree limbs while still 50 miles offshore and washed out a section of the boardwalk on the north end of town, Atlantic City Mayor Lorenzo Langford told CNN. He said there were still "too many people" who didn't heed instructions to evacuate, and he urged anyone still in town to "hunker down and try to wait this thing out."
"When Mother Nature sends her wrath your way, we're at her mercy, and so all we can do is stay prayerful and do the best that we can," Langford said.
And in Seaside Heights, about 30 miles north of Atlantic City, Police Chief Thomas Boyd told CNN, "The whole north side of my town is totally under water."
Mass transit grinds to a halt
In New York, lower Manhattan's Battery Park recorded nearly 14-foot tide, smashing a record set by 1960's Hurricane Donna by more than 3 feet. The city had already halted service on its bus and train lines, closing schools and ordering about 400,000 people out of their homes in low-lying areas of Manhattan and elsewhere.
Flooding forced the closure of all three of the major airports in the area, LaGuardia, John F. Kennedy and Newark Liberty. Water seeped into subway stations in Lower Manhattan and into the tunnel connecting Lower Manhattan and Brooklyn, while high winds damaged a crane perched atop a Midtown skyscraper under construction, forcing authorities to evacuate the surrounding area.
An emergency vehicle plows through floodwaters on Monday in Dewey Beach, Delaware.
A person tries to cross the street during the storm on Monday in Atlantic City.
A traffic sign warns motorists west of Philadelphia on Monday.
A downed tree and fallen power lines lie over homes Monday on Harvard Street in Garden City, New York.
Kira Brizill leads family members as high tide and winds flood the street on Monday in Freeport, New York.
Superstorm Sandy dumped a lot of rain, flooding a part of Greenpoint, Brooklyn
New York Mayor Michael Bloomberg told reporters there was an "extraordinary" amount of water in Lower Manhattan, as well as downed trees throughout the city and widespread power outages.
"We knew that this was going to be a very dangerous storm, and the storm has met our expectations," he said. "The worst of the weather has come, and city certainly is feeling the impacts."
The storm was blamed for more than 2.8 million outages across the Northeast. About 350,000 of them were in the New York city area, where utility provider Con Edison reported it had also cut power to customers in parts of Brooklyn and Lower Manhattan to protect underground equipment as the storm waters rose.
But as water crept into its substations, Con Ed said it had lost service to about 250,000 customers in Manhattan -- including most of the island south of 39th Street.
Five things to know about Sandy.
At least five people had been killed in storm-related incidents in New York state, including three killed by trees falling on homes in Queens and in the town of New Salem, near Albany, city and state officials said. Falling trees were also blamed for three deaths reported in New Jersey and one in Connecticut, authorities there told CNN.
In West Virginia, a woman was killed in a car accident after the storm dumped 5 inches of snow on the town of Davis, said Amy Shuler Goodwin, a spokeswoman for Gov. Earl Ray Tomblin's office.
Waves slam into the sea wall in Scituate, Massachusetts, on Monday.
Chris Losordo carries his father, Vin, across a flooded road in Falmouth, Massachusetts, on Monday.
Floodwaters cover the streets of Rehoboth Beach, Delaware, on Monday.
Waves crash against a previously damaged pier in Atlantic City, New Jersey, as Hurricane Sandy approaches landfall on Monday.
High winds broke part of a crane boom on this building under construction in Manhattan, causing several nearby buildings to be evacuated.
And before hitting land, it overwhelmed the sailing ship HMS Bounty, a replica of the historic British vessel, off North Carolina. Fourteen of the ship's crew of 16 were rescued, but the body of one deckhand was found Monday evening and the ship's captain was still missing Monday night, the Coast Guard said.
Sandy had already claimed at least 67 lives in the Caribbean, including 51 in Haiti.
Sandy's storm surges were boosted by a full moon, which already brings the highest tides of the month. And forecasters said the storm was likely to collide with a cold front and spawn a superstorm that could generate flash floods and snowstorms.
"It could be bad," said U.S. Coast Guard Rear Adm. Steven Rattior, "or it could be devastation."
Mass transit shut down across the densely populated Northeast, landmarks stood empty and schools and government offices were closed. The National Grid, which provides power to millions of customers, said 60 million people could be affected before it's over.
On Fire Island, off Long Island, the water rose above promenades and docks on Monday afternoon, homeowner Karen Boss said. Boss stayed on the island with her husband despite a mandatory evacuation order. She said they own several properties and a business there and had weathered previous storms.
A lone figure makes his way down Seventh Street in Lindenhurst, New York, on Monday.
Obama steps off Air Force One on Monday after arriving at Andrews Air Force Base.
People walk on a flooded street after Hurricane Sandy hit Port-au-Prince, Haiti, on Thursday.
A house ruined by heavy flooding from Hurricane Sandy sits abandoned in Port-au-Prince, Haiti, on Thursday.
