A massive storm brought snow, sleet, and freezing rain across a wide swath of the US South on Sunday — causing dangerously icy roads, immobilizing snowfalls and power losses to hundreds of thousands of people.

Accidents on snow-covered interstates are causing major delays, hundreds of flights have been cancelled and drivers in North Carolina and Virginia are getting stuck in snow or losing control on icy patches. Meanwhile, kids and the young at heart are taking advantage of heavy snow with snowball fights and snowmen.

North Carolina Gov. Roy Cooper strongly urged residents to stay off the roads Sunday, asking drivers not to put lives of first responders needlessly at risk. Cooper said emergency crews, including the National Guard, had worked overnight to clear traffic accidents on major roadways. One tractor-trailer ran off a road and into a river, Cooper said.

“Stay put if you can,” Cooper said. “Wrap a few presents, decorate the tree, watch some football.”

Governors and local officials in several states declared emergencies ahead of the storm crossing several Southern states, which is hitting portions of North Carolina and Virginia particularly hard.

Officials have warned residents to prepare emergency kits and stay off roads in affected areas. Schools districts in North Carolina and Virginia have announced they’ll be closed Monday.

“Virginians should take all necessary precautions to ensure they are prepared for winter weather storm impacts,” said Virginia Gov. Ralph Northam.