CHICAGO (AFP) - Hundreds of thousands of people were left shivering in the dark after a massive ice and snowstorm cut a swath across the United States Wednesday, knocking down power lines, snarling traffic, grounding flights and forcing schools to close. Freezing rain on the southern end of the storm covered trees and bridges with brilliant ice crystals but made roads incredibly slick and dangerous from Texas to Pennsylvania. At least a dozen deaths were reported. The northern side of the snow dumped as much as a foot of snow in some areas of Ohio and the US east coast. And with a cold front moving in behind the storm it could be days before the ice melts and weeks before all the damage is repaired, officials warned. The storm formed Monday over the southern plain states and Texas and moved steadily east and north, Sullivan said. Some areas got ice on top of snow. The Oklahoma Highway Patrol responded to more than 1,000 weather related collisions on Monday and Tuesday, 130 of them involving injury. Two people were killed. More than a hundred accidents were reported from midnight to 9 am Wednesday in the city of Dallas alone and a two people died in Texas, the Dallas Morning News reported. Heavy ice brought down tree limbs and power lines, blew out transformers and caused a number of fires in Kentucky, where several cities were completely without power. Three people were killed in Arkansas, where emergency shelters were opened after power and phone lines were knocked down by the ice, officials said. Five storm-related deaths were reported in Missouri. But the storm also provided for some lighter moments. President Barack Obama, who recently moved from the icy city of Chicago to relatively temperate Washington, joked about how the US capital proved unable to cope with some winter weather. "As my children pointed out, in Chicago school is never cancelled," Obama told reporters. "In fact, my 7-year-old pointed out that you would go outside for recess. You wouldn't even stay indoors. So it's - I don't know. We're going to have to try to apply some Chicago toughness. I'm saying, when it comes to the weather, folks in Washington don't seem to be able to handle things."