A deadly ice storm stranded scores of people on slick roads and knocked out power to hundreds of thousands of US homes as winter-weary Americans dug in against Mother Nature's latest blow.
More than 3,700 flights due to take off Thursday were canceled across the United States due to the wintry blast, including well over half of flights at the busiest US airport, Atlanta's Hartfield International, airline monitors said.
The National Weather Service began warning days ago that a "mammoth dome" of Arctic air would settle over the eastern United States to form a "paralyzing ice storm."
"The ice accumulations remain mind-boggling, if not historical," it said, warning that more than an inch (2.5 centimeters) of ice could fall from Georgia to South Carolina.
The massive storm -- which stretched from Alabama to Virginia -- was also expected to dump as much as a foot (30 centimeters) of snow.
It was set to strengthen as it climbed northward along the eastern seaboard Thursday, with snowfall totals topping 18 inches by the time the storm reached the far northeastern New England region.
Accidents and abandoned cars caused massive traffic jams in North Carolina, with the usually temperate cities of Raleigh and Charlotte transformed into ice- and snow-covered parking lots.
North Carolina Governor Pat McCrory urged residents to stay indoors -- even if it means sleeping at work -- rather than risk the roads.
"If you're in a safe warm place, stay in a safe warm place," McCrory told CNN.
"We've already had two fatalities and we don't want to see more."
Two deaths in Georgia were blamed on the storm so far, local media reported. That put the death toll at four, though it was unofficial and still early.
Many Atlanta residents stayed home, after the gridlock caused by a much weaker storm two weeks ago stranded thousands of people. It took days to clear the highway of abandoned vehicles at the time.
- Stranded travelers -
Specialty website FlightAware said airlines have already canceled 3,703 flights for Thursday, including more than half of flights to and from New York and Washington.
"We expect that the number of cancellations will continue to rise as freezing precipitation hits major airports in Philadelphia, DC and New York," the service said.
Seventy percent of flights in the Delta Airlines hub of Atlanta were cancelled Wednesday and 55 percent of those in the US Airways hub of Charlotte, North Carolina, according to FlightAware.
- Emergency aid deployed -
President Barack Obama declared states of emergency in Georgia and South Carolina in order to deploy federal resources to help deal with the storm.
The Federal Emergency Management Agency said it was also in contact with state emergency offices in Pennsylvania, Maryland and Virginia to assess their assistance needs as the storm builds.
In addition to the FEMA aid, various localities across the region were readying emergency shelters at churches and recreation centers where residents could stay warm should they lose power.
Power companies sent out convoys of utility crews to trim tree limbs in advance of the storm's arrival, hoping to head off potentially massive cuts in power.
Georgia Power said its crews were working through the storm to restore power after the freezing rain knocked down power lines and trees.
While it managed to restore power to 70,000 customers by Wednesday afternoon, outages were increasing as the freezing rain continued and more than 130,000 people in the Peach State were without power as the sun began to set.
More than 230,000 customers lost power in South Carolina, local utilities reported.
The severe weather has been playing havoc with US businesses and governments' bottom line.
Payrolls firm ADP said last week that wintry onslaught has taken a toll on job growth.
Oil prices, by contrast, have been propelled higher by the extra-cold weather and succession of winter storms.
State and local governments are scrambling to cover the cost of clearing the snow, especially as road salt prices skyrocket amid shortages.
Farmers and rural residents are also facing high prices and shortages of the propane used to heat their homes and barns.