A fierce winter storm has left a trail of destruction across the southern US, devastating communities and killing three people in Louisiana.
The weather has also left tens of thousands without power across six states.
To the east, an estimated 11 million people in Florida and Georgia are still facing the threat of tornadoes.
The storm system also brought blizzard-like conditions to the Midwest.
In Louisiana, officials have so far confirmed three deaths and dozens of injuries as a result of the storm. In one incident, a 56-year-old woman in St Charles Parish near New Orleans was killed after a tornado destroyed her home.
Communities across the state reported severe damage, including downed power lines and collapsed buildings. In Jefferson Parish – a suburb of New Orleans – the sheriff’s office said that homes and businesses in the area had “suffered catastrophic damage”.
One Louisiana resident, Michael Willis, told the BBC’s US partner CBS that a close encounter with a tornado near the town of Harvey was “the scariest thing” he has ever experienced.
The tornado lifted him up while he was sitting in his car, a large SUV, while debris smashed through his windshield and passenger window.
“It happened fast,” he said. “I’m looking at wood, buildings, all in the same spin, like it’s spinning with me and then it just slung me out.”
Earlier, Louisiana health officials confirmed that a 30-year-old woman and her eight-year-old son were found dead in Caddo Parish in the northwest corner of the state.
As of 07:00 local time (13:00 GMT) on Thursday, about 10,000 people were still without power in various parts of the state, according to website poweroutage.us.
Power outages were also reported in Wisconsin, Michigan, Minnesota, Pennsylvania and West Virginia. In Wisconsin alone, 70,000 people were without power Thursday morning.
In Florida and Georgia, millions of people were still under tornado watch as the sun rose on Thursday, with authorities warning residents of “damaging to destructive winds”. The severe risk was expected to end by Thursday afternoon.
Further north, forecasters expect snow and freezing rain to continue through at least Friday afternoon across a large swathe of the country from the east coast to the Midwest.
“This system is notable for the fact that it’s going to impact areas all the way from California to eventually the Northeast,” National Weather Service meteorologist Frank Pereira told CBS.
In South Dakota, the snow – which was nearly two feet (0.6 metres) high in some areas – prompted officials to close a 320-mile (514km) stretch of highway.
Additionally, in Minnesota, the Star Tribune reported that blizzard-like conditions were likely until Thursday, with as much as 2.5 feet (0.75 metres) of snow likely by the weekend.
In Canada, large parts of Ontario remained freezing rain warnings on Thursday, while snowfall warnings were issued for areas including Ottawa, Montreal and Quebec City.
