MERRILL, Michigan -- Authorities say a Michigan man celebrating his 21st birthday accidentally shot his best friend and then killed himself in grief.WJRT-TV reports Zachary Woodcock shot himself minutes after he accidentally shot 21-year-old Richard Skillman, who died at the scene.Saginaw County Sheriff's Lt. Mike Gomez says Woodcock was celebrating his birthday Jan. 19 with friends in his apartment in Merrill, northwest of Detroit.Gomez says Woodcock returned from his bedroom with a handgun that "went off and struck Mr. Skillman in the chest."As others were helping Skillman, witnesses told police that Woodcock left the apartment.Gomez says "they heard a shot, walked out and there he was."About 10 guns later were found in the apartment and Skillman's car.----------