Winds of up to 115 miles per hour whipped across the Eastern Seaboard, ripping power lines from poles and snapping trees in half. Hospitals, emergency call centers and other crucial facilities were holding up, but officials said it could get much worse as Irene churns north.
Gasoline supplies were falling as drivers top off their tanks on their way out of town. Pump prices rose about 3 cents per gallon overnight in New Jersey and Pennsylvania.
The power losses were heavily concentrated in Virginia and North Carolina, where Irene charged ashore early Saturday morning.
Progress Energy reported 273,000 customers without power, with much of the damage in Wilmington and Wrightsville Beach, N.C.
"We expect those numbers to increase," Progress spokeswoman Julia Milstead said.
Dominion Resources reported outages for 340,000 of its customers in Virginia and North Carolina, while Duke Energy said 14,600 customers were in the dark. Pepco, which serves Maryland, Washington D.C., parts of New Jersey and Delaware reported more than 1,900 outages and Baltimore Gas & Electric said 2,300 of its customers were without power.
New York's biggest utility, Consolidated Edison, said it could cut power to the city's most vulnerable areas if the storm causes serious flooding. ConEd operations chief John Miksad said the utility doesn't expect to cut power before the storm hits, but flooding Sunday could bring a shutdown to areas including the southern tip of Manhattan. That would cut off power to major Wall Street institutions through parts of next week.
The New York Stock Exchange has backup generators and can run on its own, a spokesman said Friday. The exchange expects to open as usual Monday morning, though it may change plans depending on the severity of the storm.
New York is regularly blasted by winter storms, but Miksad said this hurricane will be different. Irene's wind will pack a stronger punch than a nor'easter last March that knocked out power to 175,000 customers, he said.
ConEd has called in crews from as far away as Colorado to help repair damage from the storm.
Irene is expected to be a brutal test for Middle Atlantic States, which haven't seen a hurricane since 1999. The storm is expected to stay just offshore - and thus retain much of its power - as it inches up the coast from North Carolina to New England. When a hurricane hits land, it quickly loses steam.
The entire Eastern Seaboard lies in the storm's projected path. Flooding and damage from winds are likely. North Carolina, Virginia, Maryland, New Jersey, New York, Connecticut and Rhode Island have declared emergencies. For the first time, New York City ordered people in low-lying areas to evacuate.
Power companies have called in several hundred workers from surrounding states to help. Crews were rushing out between bands in the hurricane, when the wind and rain eases. They're looking for the worst damage first at towering transmission lines, where an outage could put an entire county in the dark.
The storm already has shortened gasoline supplies as refueling barges wait out the storm off the coast. Experts are now bracing for widespread power outages that could switch off automated delivery networks for gasoline stations, forcing them to individually call terminals for more fuel. That would slow down fuel deliveries, and motorists likely would be stuck in longer lines as gas pumps dry up.
"Power is the lifeblood of oil supply on the East Coast," said Ben Brockwell of the Oil Price Information Service, which tracks gasoline shipments around the country.
Some gas stations in New Jersey reported that they'd run out of fuel. Those shortages could become more widespread.
Retail gas prices were mostly unchanged in many cities that are expected to be hit this weekend. Rules against price gouging at gas stations took effect throughout Middle Atlantic states. Authorities will be on the lookout for stations that try to take advantage of panicked drivers.
Pump prices jumped as much as 3 cents per gallon overnight to $3.44 per gallon in Philadelphia and $3.49 in New Jersey's Atlantic-Cape May metro area. They seemed to hold in other areas, rising a penny or so on average in Maryland, Virginia and the Carolinas.
The Colonial Pipeline, which transports 100 million gallons of gasoline and other fuels from the Gulf Coast to the Northeast, stopped fuel deliveries to Selma, N.C. and to Virginia's Tidewater area as the storm knocked out power. Pipeline spokesman Steve Baker said the pipeline may cut off deliveries further in Virginia and Maryland as the storm moves north.
Refineries, which make fuel from oil, have started to slow down operations as Irene approaches.