S3·E21 Sanctuary

Depressed, Vinnie contemplates suicide, then hears church bells. He goes to confession and breaks down, begging Father Pat to help him. Frank goes to Seattle to look for Vinnie. Vinnie tells Father Pat about the toxic dumping, and the priest arranges a press conference. Frank finally finds Vinnie at the church. Kousakis overhears the plan to expose him on the news and shoots at them, wounding Frank and Father Pat. Vinnie and Dan chase Kousakis. Dan finds out Frank is in critical condition and goes to the hospital. After trying to revive Frank, the doctors give up when he flat lines. (source: http://www.plasticcow.com/wiseguy)