A massive snowstorm has brought much of the eastern US to a standstill, affecting some 85 million people.
The blizzard has dumped 40in (102cm) of snow in some areas, with 11 states declaring emergencies.
All non-essential travel is banned in New York, with officials believing it could be one of the city's worst snowstorms.
At least 18 deaths — many from traffic accidents — have been blamed on the severe weather since Friday.
In all, 20 states have been affected by the fierce storm.
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Tens of thousands of homes are now without power and traffic jams lasting more than 12 hours were reported in Kentucky and Pennsylvania on Saturday.
Map showing snowfall across US
In rural Virginia — parts of which had more than 30in of snow — there were more than 1,000 car crashes and two people died of hypothermia.
The heaviest unofficial snowfalls recorded by mid-afternoon on Saturday included:
40in (102cm) — Berkeley County, West Virginia
35.5in (90cm) — Morgan County, West Virginia
34in (86cm) — Washington County, Maryland
In New York, travel restrictions came into effect in the city at at 14:30 (19:30 GMT), with transport being suspended and bridges shut.
Emergency vehicles and workers carrying out repairs are being allowed to use roads — but those driving non-essential vehicles risk being arrested
Almost all flights into the city have been cancelled.
Mayor Bill de Blasio said up to 28in of snow might fall, making it one of the five worst winter storms in the city.
New York's highest previous snowfall, 26.9in, was recorded in February 2006.
"This is going to be one of those generational events, where your parents talk about how bad it was," said Ryan Maue, a meteorologist with WeatherBell Analytics.
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On the Pennsylvania Turnpike, several hundred people have been stranded in vehicles for almost a day.
Among them are close to 250 students from the University of Mary in North Dakota. Monsignor James Shea, president of the university, told the BBC that "spirits are good and no-one is panicking".
Further south in Kentucky, a 35-mile (56km) traffic jam has cleared, after thousands of drivers found themselves stranded overnight on Interstate 75 by heavy snow and a number of accidents.
The Red Cross erected shelters along the highway for those left in the traffic jam.
In other developments:
More than 7,00 weekend flights have been cancelled in the eastern US, with 4,300 on Saturday alone
Airports in Washington DC will remain closed on Sunday
More than 150,000 properties lost power in North Carolina
Another 90,000 people were without power in New Jersey, while high tides have led to some heavy flooding in the south of the state
States of emergency have been declared in New York, Tennessee, Georgia, Kentucky, North Carolina, New Jersey, Virginia, West Virginia, Maryland, Pennsylvania, the District of Columbia
The US federal government closed down at noon on Friday. President Barack Obama is remaining at the White House.
Residents in the capital and surrounding suburbs in Virginia and Maryland have been warned the snowfall could eclipse the district's record of 28in that fell during a two-day period in 1922.