Last Updated Feb 21, 2015 9:28 PM EST
Snow, sleet, freezing rain and bitterly cold temperatures proved to be a deadly combination Saturday in the southern U.S.
Officials in Tennessee said at least 18 people died, including nine from hypothermia and five from car accidents on slick and snowy streets.
Tennessee Gov. Bill Haslam upgraded the state of emergency to Level 2, a major disaster, as forecasters warned of possible flash flooding.
Overall, 43.3 million Americans were under a winter storm warning Saturday night.
Snow fell in the nation's capital, and the storm is expected to continue heading north, hitting major cities along the East Coast through early Sunday.
The National Weather Service predicted three to eight inches of snow in some parts of Northern Virginia. Western Maryland could get up to a foot.
Yet more snow is called for in Boston, which is struggling to dig out from record snowfalls. In some neighborhoods, parking has become a major headache as residents attempt to save precious parking spaces.
Northwest of the city in Westford, Massachusetts, emergency responders fought to save victims buried in a barn collapse -- four-legged victims.
A heavy snowpack brought the roof down on seven horses owned by Bob Haig Sr. Local veterinarians volunteered their help.
"It's just beautiful," Haig said after the rescue. "There were just so many people here, and I'm so thankful, and I'm going to cry again."
While some people struggled, others took advantage of an outdoor wonderland. A frozen waterfall in North Carolina provided the perfect opportunity for ice climbing. And flat ground in Washington, D.C., proved no obstacle for a kiteboarder near the Washington Monument.
While the cold has turned the iconic fountain in New York City's Bryant Park into an ice sculpture, some areas in and around the city experienced flooding.
Forecasters warned that freezing temperatures expected Monday would likely cause much of that water to ice over, making travel extremely hazardous.