Tens of thousands of Duke Energy customers in southern Indiana are without electricity in the wake of the ice storm.Company spokesman Lou Middleton says crews are in the field assessing the damage."We are looking at just about 40,000 people out in Clarksville, about 16,700 who are out in the Corydon and Salem area, we combined those two areas. In Madison we're looking at just shy of five thousand customers who are out," Middleton said Wednesday morning.Thousands of people are also without power in Floyd, Crawford, Harrison and other counties.Middleton says it's difficult to speculate when service might be restored, as ice-covered limbs will continue to fall over the next several days.