Hurricane Irene churned northward toward Canada, leaving a water-logged East Coast to pick up the pieces and officials stewing that the worst was not yet over, dpa reported.
By late Sunday, at least 19 deaths in six states were blamed on Irene since she made landfall early Saturday. Officials warned that the heavy rain dumped along the 1,200-kilometre Atlantic coast was swelling rivers, breaking dams and threatening flash floods over the coming days.
"If you don't have to go to work (Monday), don't go to work. Travel around the state is going to be extremely difficult," New Jersey Governor Chris Christie said at a broadcast press conference.
He read a list of a dozen rivers threatening to flood, including the mighty Delaware River.
The state of Vermont, the last target on Irene's list before departing to Canada, carried out a last minute evacuation of its capital, Montpelier, as water flooded its streets and swamped vehicles.
Although New York City breathed a sigh of relief that Irene had been downgraded to a tropical storm by the time it arrived early Sunday, Federal Emergency Management Agency director Craig Fugate snapped at any idea of self-congratulation - or second-guessing about evacuations and other preparations.
"People are saying they've dodged a bullet ... (but) people have lost lives. I don't think you can say we dodged a bullet," Fugate was quoted as saying by the Los Angeles Times.
US President Barack Obama expressed condolences for those "who lost loved ones and those whose lives have been affected by the storm."
He noted that while the storm had weakened, "many Americans are still at serious risk of power outages and flooding."
"The impacts of this storm will be felt for some time, and the recovery effort will last for weeks or longer," he said.
An estimated 4 million people were without electricity, CNN reported. Air, rail and bus transport from North Carolina to Boston and within major cities will on Monday offer only sketchy service, posing a nightmare for commuters trying to get to work.
New York's major airports - Newark, JFK and LaGuardia - were to reopen Monday morning for service, Christie said.
Initial damage estimates ranged from 7 to 20 billion dollars as of Sunday, according to the Consumer Federation of America and Peter Morici, an economist and professor at the University of Maryland.
Factoring in the loss of economic activity for at least two days, if not more, through the coming week, losses could reach as high as 45 billion dollars, Morici said.
In New York City, large areas of the city experienced "serious flooding," Mayor Michael Bloomberg said. Both the East River and Hudson River left their banks as Irene blew through at tropical storm level.
In North Carolina, more than 2,000 people who refused to evacuate from Hatteras Island were cut off from the mainland after wind-whipped sea water carved a new channel across a connecting road, CNN reported.
One sign that things were about to get back to normal, however, was the announcement by New Jersey's Christie that tolls would be reinstated on Monday. They had been suspended over the weekend as the state government evacuated 1 million people from popular beach resorts including Atlantic City.
After considerable hype on Cable TV in advance of the storm, broadcasters on Sunday questioned whether such drastic measures had been necessary: Bloomberg evacuated 370,000 people, Christie 1 million, and so on.
In fact, the efficient preparations and evacuations were in stark contrast to 2005, when Hurricane Katrina killed more than 1,800 people in New Orleans.
Christie was impatient with the suggestion that governments had overreacted or over-prepared.
"By moving 1 million people off the Jersey shore, we saved lives," he said. "My job as governor is to protect the people we serve."