Feds probe relationship between N.C. regulators and Duke Energy after spill

      |Federal prosecutors issued at least 23 subpoenas investigating the relationship between Duke Energy and North Carolina state regulators after wastewater from a retired plant coated an 80-mile stretch of the Dan River with toxic sludge. Prosecutors are examining whether regulators were influenced by the utility with money, preferential treatment or promise of future employment. Mark Strassmann reports.