ATLANTIC CITY, N.J. — Hurricane Sandy wheeled toward land as forecasters feared Monday, raking cities along the Northeast corridor with rain and wind gusts, flooding shore towns, washing away a section of the Atlantic City Boardwalk, and threatening to cripple Wall Street and New York's subway system with a huge surge of corrosive seawater.

By midday, the storm was picking up speed and was expected to blow ashore in New Jersey or Delaware by the evening, hours sooner than previously expected. Forecasters warned it would combine with two other weather systems — a wintry storm from the west and cold air rushing in from the Arctic — to create an epic superstorm.

From Washington to Boston, subways, buses, trains and schools were shut down and more than 7,000 flights grounded across the region of 50 million people. The New York Stock Exchange was closed. And hundreds of thousands of people were under orders to move to higher ground to await the storm's fury.

President Barack Obama and Mitt Romney suspended their campaigning with just over a week to go before Election Day.

At the White House, the president made a direct appeal to those in harm's way: "Please listen to what your state and local officials are saying. When they tell you to evacuate, you need to evacuate. Don't delay, don't pause, don't question the instructions that are being given, because this is a powerful storm."

Authorities warned that New York City and Long Island could get the worst of the storm surge: an 11-foot onslaught of seawater that could swamp lower Manhattan, flood the subways and damage the underground network of electrical and communications lines that are vital to the nation's financial capital.

Because of Sandy's vast reach, with tropical storm-force winds extending almost 500 miles from its center, other major cities across the Northeast — Washington, Baltimore, Philadelphia and Boston — also prepared to for the worst.

"The days ahead are going to be very difficult," Maryland Gov. Martin O'Malley said. "There will be people who die and are killed in this storm."

Sheila Gladden evacuated her home in Philadelphia's flood-prone Eastwick neighborhood and headed to a hotel.

"I'm not going through this again," said Gladden, who had 5 1/2 feet of water in her home after Hurricane Floyd in 1999.

By midafternoon, the storm was 85 miles southeast of Atlantic City, its winds at 90 mph. It had speeded up to 28 mph and had begun the turn toward the coast that forecasters had feared.

As the storm closed in, a crane dangled precariously in the wind off a 65-story luxury building in New York City, and the streets were cleared as a precaution.

The storm washed away an old section of the world-famous Atlantic City Boardwalk and left most of the city's emptied-out streets under water. All 12 casinos in the city were closed, and some 30,000 people were under orders to evacuate.

"When I think about how much water is already in the streets, and how much more is going to come with high tide tonight, this is going to be devastating. I think this is going to be a really bad situation tonight," said Bob McDevitt, president of the main Atlantic City casino workers union.

New Jersey Gov. Chris Christie, addressing those who were told to evacuate the state's barrier islands, said in his usual blunt way: "This is not a time to be a show-off. This is not a time to be stupid. This is the time to save yourself and your family."

In New York City, where 375,000 people were ordered to clear out, authorities closed the Holland Tunnel, which connects New York and New Jersey, and a tunnel between Manhattan and Brooklyn. Street grates above the subway were boarded up, but officials still worried that seawater would seep in and damage the electrical switches.

In the morning, water was already splashing over the seawalls at the southern tip of Manhattan and had matched the levels seen during Hurricane Irene in August 2011. Still, people were out jogging, walking their dogs and even taking children out in strollers amid gusts of wind.

"We're high up enough, so I'm not worried about flooding," said Mark Vial, who was pushing his 2-year-old daughter, Maziyar, in a stroller outside their building, where they live on the 15th floor. "There's plenty of food. We'll be OK."

Water was already a foot deep on the streets of Lindenhurst, N.Y., along the southern edge of Long Island, and the canals around the island's Great South Bay were bulging two hours before high tide.

The major American stock exchanges closed for the day, the first unplanned shutdown since the Sept. 11 attacks in 2001. Wall Street expected to remain closed on Tuesday. The United Nations canceled all meetings at its New York headquarters.

New York called off school on both Monday and Tuesday for the city's 1.1 million students, and the more than 5 million people who depend on its transit network every day were left without a way to get around.

Sandy, a Category 1 hurricane, was blamed for 69 deaths in the Caribbean before it began traveling northward, parallel to the Eastern Seaboard. Forecasters said the combined Frankenstorm could bring close to a foot of rain in places, a potentially lethal storm surge of 4 to 11 feet, and punishing winds that could cause widespread power outages that last for days. Up to 3 feet of snow was forecast for the West Virginia mountains.

About 90 miles off Cape Hatteras, N.C., the Coast Guard rescued 14 crew members by helicopter from the HMS Bounty, a replica 18th-century sailing ship that sank in the storm. The Coast Guard searched for two other crew members. The ship was built for the 1962 Marlon Brando film "Mutiny on the Bounty."

The rescued had donned survival suits and life jackets and boarded two lifeboats after the ship began taking on water. They were plucked from 18-foot seas just before sunrise.

O'Malley, the Maryland governor, said a fishing pier in the beach resort of Ocean City, not far from a popular boardwalk and amusement park, was "half-gone." The area had been ordered evacuated on Sunday.

Craig Fugate, chief of the Federal Emergency Management Agency, said FEMA teams were deployed from North Carolina to Maine and as far inland as West Virginia, bringing generators and basic supplies that will be needed in the storm's aftermath.

"I have not been around long enough to see a hurricane forecast with a snow advisory in it," Fugate told NBC's "Today" show.

___

Breed reported from Raleigh, N.C.; Contributing to this report were AP Science Writer Seth Borenstein in Washington; Katie Zezima in Atlantic City, N.J.; David Porter in Pompton Lakes, N.J.; Wayne Parry in Point Pleasant Beach, N.J.; and David Dishneau in Delaware.