More than a million customers were without power Sunday as a massive winter storm coated tree branches and power lines with heavy ice across the South. Tennessee was the hardest hit, with more than 300,000 customers losing power, while Texas, Mississippi and Louisiana each had more than 100,000 customers in the dark, according to poweroutage.com. The ice and snowfall were expected to continue through Monday in much of the country, followed by very low temperatures, the National Weather Service said.