COLUMBIA - A winter freeze loosened its grip across much of South Carolina on Tuesday as slowly rising temperatures began melting ice, sleet and snow.
But slick roads continued to make driving risky and strong winds threatened to slow crews working to restore power to about 300,000 customers without electricity.
Six people died in weather-related traffic accidents during the storm, the Highway Patrol said.
Winter weather pelted the Upstate with sleet and snow starting Sunday. Up to 2 inches of sleet was reported in Lancaster County and an inch of ice and sleet accumulated in Oconee County.
Mostly freezing rain fell in central South Carolina, according to the National Weather Service.
Meteorologist Jeff Linton said the ice storm may be the worst the state has seen since December 2002, when roughly 300,000 customers in the Upstate were left without power.
Some freezing rain reached inland parts of the coast Monday afternoon and evening, but counties along the coast reported little accumulation.
Ice forced laden tree limbs onto frozen power lines. Crews were working to restore power Tuesday, but some worried that a burst of strong winds could slow progress.
In the Pee Dee region, temperatures were expected to rise slightly, reaching the 50s today. Winds were predicted to reach as high as 20 mph Tuesday.
"If the wind starts blowing that could cause (trees) to snap and come back across the lines," said Eddie Richardson, spokesman for Mid-Electric Cooperative, which had 6,000 Midlands customers without power Tuesday afternoon.
S.C. Electric and Gas still had 150,000 customers without power Tuesday, and Progress Energy reported 70,000 customers in the dark. The Electric Cooperatives of South Carolina said 68,000 were without power. Duke Power, which mostly serves the Upstate, reported 6,200 customers without power but was expecting lights back on by midnight Tuesday.
Few power outages were reported in the Upstate, which took the brunt of the winter precipitation Sunday night and early Monday, but slick roads caused collisions.
Troopers responded to more than 2,500 accidents by Tuesday morning, most in the Upstate and in the Midlands.
In Union County, the National Guard was deployed to help emergency personnel after the county's rescue squad and firefighters were hampered by icy conditions, The Union Daily times reported.
A 911 official reported to the National Weather Service that road conditions were "the worst ... ever seen in this county." At least one sand truck overturned and at least half-dozen ambulances were stranded, some were stuck with patients still inside.
State trucks were down to 160 tons of sand for Union County roads after spreading more than 400 tons since Sunday.
"When that's gone ... I don't know when we'll get more," said Ronnie Spencer, resident maintenance engineer with the state Transportation Department. "The problem is, it keeps freezing over what we have done."
The department had more than 900 employees working to clear roads and bridges Tuesday morning.
Gov. Mark Sanford delayed state office openings in 37 counties until noon Tuesday.