Earl D. “Skip” Sheppard, 49, who was serving a life sentence for the 1988 deaths of six Kansas City firefighters, died Saturday at a federal medical center in North Carolina. Sheppard and four other defendants were convicted at a 1997 federal trial of the arson and explosion-related deaths of the firefighters: Thomas Fry, Gerald Halloran, Luther Hurd, James Kilventon Jr., Robert McKarnin and Michael Oldham.