Hundreds of thousands of power outages were reported across the US as a monster, deadly storm hit huge sections of the country, snarling roadways with dangerous ice and forcing mass flight cancellations.
At least 12 storm-related deaths have been confirmed, including in Pennsylvania, Kansas, Texas, Louisiana, Tennessee and New York City.
As dangerous conditions persist, many power outages were reported Monday morning across Texas, Louisiana, Mississippi, Tennessee and Kentucky.
At one point, widespread heavy snow, sleet and freezing rain threatened nearly 180 million people — more than half the U.S. population — in a path stretching from the southern Rocky Mountains to New England, the National Weather Service said. It warned people to brace for a string of frigid days.
President Trump approved emergency declarations for a dozen states by Sunday, with more possible. The Federal Emergency Management Agency pre-positioned supplies, staff and search and rescue teams in numerous states, Homeland Security Secretary Kristi Noem said.
"We just ask that everyone would be smart — stay home if possible," Noem said.
The Midwest saw windchills as low as minus 40 Fahrenheit (minus 40 Celsius), meaning that frostbite could set in within minutes. The minus 36 Fahrenheit (minus 37.8 Celsius) reading in Rhinelander, Wisconsin, on Saturday morning was the coldest in almost 30 years.
The storm began dumping heavy snow on the Northeast early Sunday. By Monday morning, parts of Massachusetts had more than 20 inches (50.8 centimeters) of snow, and Boston had 18 inches (45.7 centimeters), with a few more inches expected. Schools across the state were closed on Monday because of the snowstorm.
A woman in Norwood, Massachusetts, was hit and killed by a snowplough truck on Sunday while walking with her husband.
New York City got nearly a foot of snow — 11.4 inches (29 centimeters) in Central Park, a record for the date. City schools switched to remote learning for Monday.
The Philadelphia area got upwards of 9 inches (22.9 centimeters) of snow, the most the city has seen since 2016.
Three people died while trying to shovel and clear snow during Sunday's winter storm in Lehigh County, Pennsylvania, the coroner's office said. They ranged in age from 60 to 84 years old.
Forecasters warned the storm damage, especially in areas pounded by ice, could rival that of a hurricane. Weather forecasters also said the winter storm was unusual.
Before moving northeast, the winter storm brought an unusually fierce deep freeze to a wide expanse of the South.
In Shelby County, Texas, near the Louisiana border, ice weighed down on pine trees and caused branches to snap, downing power lines. About a third of the county's 16,000 electric customers lost power on Saturday.
At least two people died in the Lone Star State: one in Austin and another, a 16-year-old girl, was killed in a sledging accident in Frisco, according to local authorities. An elderly man in Colleyville, Texas, northeast of Fort Worth, was hospitalized after being found in a pond in freezing conditions on Sunday morning.
As of Sunday night, two deaths were reported in Louisiana that resulted from the winter weather, three in Tennessee and one in Kansas, where a missing woman was found dead in the snow in Emporia, authorities said.
There were reports of vehicles hitting fallen trees and trees falling onto houses in DeSoto Parish, Louisiana, where more than half of all electric customers lost power.
In Louisville, Kentucky, emergency services on Saturday handled more than 850 calls regarding collisions, stranded motorists and other emergencies related to exposure to cold, officials said, noting that the actual number could be even higher.
Officials in Georgia advised people in the state's northern regions to get off the roads Saturday and be prepared to stay put for at least 48 hours.
In Rabun County, one of the hardest hit parts of Georgia, officials say they've had fallen trees and downed power lines, along with icy and hazardous roadways around the county. Even when the storm moves out of the area, officials are warning residents not to get on the roads, as below-freezing temperatures will cause ice to reform, making travel dangerous.
After earlier putting 500 National Guard members on standby, Georgia Governor Brian Kemp announced Saturday that he was deploying 120 of them to northeast Georgia "to further strengthen our response in the hardest hit areas."
Churches moved Sunday services online, and the Grand Ole Opry in Nashville, Tennessee, decided to hold its Saturday night radio performance without fans. Mardi Gras parades in Louisiana were canceled or rescheduled.
Jami Joe of Nashville, 41, feared her electricity might not last as ice-heavy limbs from oak and pecan trees continued to crash around her house. "It's only a matter of time if a limb strikes a power line," she said.
Nashville Electric Service said Sunday afternoon there were nearly 200,000 customers without power and warned the outages could last days or longer.
School closings were already announced for Monday in numerous cities, including Dallas, Houston and Memphis.
Some universities in the South canceled classes for Monday, including the University of North Carolina at Chapel Hill and the University of Mississippi's main campus in Oxford.
Oxford Utility crews were also pulled from their jobs during the overnight hours. At least 180,000 customers across the state of Mississippi do not have power, Governor Tate Reeves said at a news conference Sunday afternoon.
Reeves said he is requesting help from FEMA to send cots and food to warming shelters, as well as generators to long-term care facilities and hospitals that don't have adequate backup generators.
On the highways, crews clearing downed trees were feeling overwhelmed.