The Los Angeles Times reported Irene was blamed for at least eight deaths in North Carolina, Virginia and Florida, and had left a million customers without power. The newspaper said the youngest fatality was an 11-year-old boy killed when a tree crashed into his apartment building in Newport News, Va.
The storm forced the evacuation of more than 2 million people and was responsible for the cancellation of about 10,000 commercial airline flights, the Times said.
"Staying behind is dangerous, staying behind is foolish and it's against the law," New York Mayor Michael Bloomberg said.
In a television appearance, New Jersey Gov. Chris Christie urged about 600 seniors to leave their Atlantic City high-rises.
"You're correct that I cannot make you leave your home and I certainly do not intend to place you under arrest to get you to leave," the Times quoted Christie as saying."But if you stay where you are, you're putting yourself in danger as well as your loved ones."
The National Hurricane Center in Miami said in its 11 p.m. advisory Irene was about 70 miles south-southwest of Ocean City, Md., and about 255 miles south-southwest of New York City.
Wind gusts up to 67 mph was reported as far south as Cape Hatteras, N.C., and a gust up to 52 mph was recorded as far north as the Philadelphia International Airport.
Philadelphia Mayor Michael Nutter said at a news conference a few bus lines had already been rerouted because of flooding, and mass transit was shutting down shortly after midnight until at least 4 p.m. Sunday.He said the Schuylkill River was expected to crest at 15 feet Sunday night, the highest level in 150 years. Thousands were already without power in the city.
The hurricane center said the preliminary water level at the Chesapeake Bay Bridge tunnel had peaked near the record level established during Hurricane Isabel in 2003. Sustained winds of 61 mph were reported at the mouth of Chesapeake Bay, with gusts to 68 mph and storm surges of about 4 feet.
The Category 1 storm's winds were hitting 80 mph on a sustained basis as it headed to the north-northeast at 16 mph, the forecasters at the center said.
With Irene's northward progress, the center said a hurricane warning was in effect from Cape Lookout, N.C., to Sagamore Beach, Mass.
A tropical storm warning was in effect for Chesapeake Bay from Drum Point northward and the tidal Potomac, north of Sagamore Beach to Eastport Maine, the U.S.-Canada border northeastward to Fort Lawrence, and the south coast of Nova Scotia from Fort Lawrence to Porters Lake.
Irene was expected to gradually increase its forward speed in the next day or so, moving over the Mid-Atlantic Coast during the night, across southern New England Sunday and into eastern Canada Sunday night.
Irene was forecast to maintain hurricane status until it makes landfall in New England, and become a post-tropical cyclone Sunday night or early Monday.
Irene's hurricane-force winds reach outward up to 85 miles and is pushing tropical storm gales out 290 miles.
Fourteen inches of rain was reported at Bunyan, N.C. and 10 or more was common across a large portion of eastern North Carolina, where storm surges of 5-9 feet were expected.
Six to 12 inches of rain is forecast for most of the Eastern Seaboard in Irene's path that could cause widespread, life-threatening flash floods.
Dangerous swells, surf and rip currents are also expected, and tornadoes are possible.
New York City shut down its subway system Saturday for the first time ever. New Jersey Transit planned to halt all its buses, trains and light rail and the Southeastern Pennsylvania Transit Authority, which serves the Philadelphia area, was also being closed down.
Christie said New Jersey's barrier islands and Cape May had been almost entirely evacuated. Atlantic City casinos had their first weather-related closing since Hurricane Gloria in 1985, The Philadelphia Inquirer said.
"The best way for to preserve human life on the Jersey Shore is for there to be no human beings on the Jersey Shore," Christie said, encouraging everyone to leave.
In Washington, President Obama, back from his vacation on Massachusetts' Martha's Vineyard, visited the National Response Coordination Center in the Federal Emergency Management Administration headquarters, where he told staff, "You guys are doing a great job obviously ... ." The president then participated in a conference call with federal and state agencies where FEMA Director Craig Fugate informed him, "We didn't start today."
"We've been doing this since early in the week," Fugate said, adding, "We are following the storm literally up the I-95 corridor."
"Each conversation I have had with state and local officials, they have confirmed to me that the relationship with FEMA has been outstanding,'' Obama said. "The inter-agency cooperation at the federal level has been outstanding. They recognize that this is going to be a tough slide getting through this thing, but they are very appreciative of the outstanding work that all of you have done.''"I have not yet heard from any of the regions as we just listened to, anybody who is suggesting that we haven't done everything we can on this front.''
Obama told the participants once the storm passes, "Obviously we are going to have to make sure that on the response and recovery phase we are just as effective and on top of it.''
"It's going to be a long 72 hours and obviously a lot of families are going to be effected," Obama said. "What we heard, the biggest concern I am having right now is the flooding and power. It sounds like that is going to be an enormous strain on a lot of states and that may take days, even longer in some cases, depending on the track of the storm.''
FEMA said the president had signed pre-disaster emergency declarations for Connecticut, Massachusetts, Maryland, New Hampshire, New Jersey, New York, North Carolina, Rhode Island and Virginia. The designations make available federal support to augment state and local efforts to save lives and to protect property and public health and safety.
FEMA positioned 18 Incident Management Assistance Teams along the coast to coordinate with state, tribal and local officials to identify needs and shortfalls affecting potential disaster response and recovery. Six national urban search and rescue teams have also been placed on alert in the event that search and rescue support is needed. The U.S. Department of Health and Human Services deployed five Disaster Medical Assistance Teams to staging areas.
Defense Secretary Leon Panetta cleared the way for the deployment of up to 6,500 active-duty military personnel if needed.
More than 1,200 National Guard members in seven states were called up, with more than 83,000 National Guard personnel available if needed.
The U.S. Army Corps of Engineers also has personnel in place.
States, localities and the Red Cross had opened more than 150 shelters in eight states as local evacuation orders went into effect.