A winter snowstorm creeping up the east coast of the United States into Canada is expected to dump more than 60 centimetres of snow in some areas, grounding planes and stranding motorists.
More than 4200 flights in the United States were cancelled or delayed on Monday, according to FlightAware.
Nearly 90,000 homes and businesses between Georgia and Maine lacked electricity, according to website PowerOutage.US.
Traffic was snarled in Toronto, Canada's largest city, as the snowstorm brought visibility to near zero, shut subway lines and left motorists stranded on local highways for hours.
Buses were at a standstill and passing pedestrians helped push cars up a street at a main commuter route in central Toronto.
The region was predicted to get up to 60cm of snow, and an extreme weather warning was in effect. Authorities asked residents to stay off the roads.
In neighbouring Quebec, the weather caused traffic accidents, including pile-ups involving dozens of vehicles that forced authorities to close some highways, according to the Canadian Broadcasting Corp.
In the eastern United States, officials likewise urged residents to stay off snowy roads on the holiday honouring slain civil rights icon Martin Luther King Jr.
Ashtabula, Ohio, on Lake Erie, recorded more than 68cm of snow, according to the National Weather Service, while parts of New York state, Pennsylvania and North Carolina received more than 50cm.
Atlanta saw its first snow in four years, according to the NWS, and some regions in North Carolina had record snowfalls.
As the storm swept north, northern Maine and New Hampshire were still due for another 5-10cm of ice and snow Monday evening, the weather service said.
Blustery conditions were predicted across much of the region into Tuesday.
Australian Associated Press
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