Preview: King of Coal

Federal prosecutors who brought the landmark case against coal company CEO Don Blankenship -- the first CEO of a major company to be convicted of a workplace safety crime -- talk about their case with Anderson Cooper. And coal miners who worked at the Upper Big Branch mine, where 29 miners were killed in 2010, talk about the mine's dangerous conditions. Anderson Cooper reports on Sunday, March 6 at 7 p.m. ET/PT.