All non-essential travel has been banned in New York, transport suspended and bridges shut as the city is being hit by one of its worst snowstorms.
Parts of the eastern US have received 40in (102cm) of snowfall in a huge blizzard that is sweeping across the region, affecting 85 million people.
Travel restrictions in New York came into place at 14:30 (19:30 GMT).
Mayor Bill de Blasio said up to 28in of snow might fall, making it one of the five worst winter storms in the city.
The city's highest previous snowfall, 26.9in, was recorded in February 2006.
Heavy snow began falling on Friday across more than 20 states.
At least 17 deaths have been blamed on the severe weather, most from traffic accidents. Emergencies have been declared in 11 states.
Tens of thousands of homes are without power and traffic jams lasting more than 12 hours were reported in Kentucky and Pennsylvania.
The heaviest unofficial snowfalls recorded by mid-afternoon included:
40in (102cm) - Berkeley County, West Virginia 35.5in (90cm) - Morgan County, West Virginia 34in (86cm) - Washington County, MarylandThe weather system affects a huge swathe of the country: from Alabama in the south to Massachusetts in the north-east.
In the latest developments in New York:
Governor Andrew Cuomo has declared a state of emergency across New York State Almost all flights into the city have been cancelled Tunnels into New York have also been closed Emergency vehicles and workers carrying out repairs are being allowed to use roads - but those driving non-essential vehicles risk being arrested Above-ground and subway train services were suspended from 16:00 local time (21:00 GMT)"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.
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.
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.