A big winter storm dumped sleet, freezing rain and snow across much of the U.S. on Sunday, bringing subzero temperatures and paralyzing air and road traffic. Power lines were draped in ice, and hundreds of thousands of people in the Southeast were left without electricity.

Around 12,000 flights across the U.S. set to take off over the weekend were cancelled as a monster storm started to wreak havoc Saturday across much of the country and threatened to knock out power fo...

Power lines were draped in ice, and hundreds of thousands of people in the Southeast were left without electricity.