Actor John Aylward, best known for his roles on "ER" and "The West Wing," has died. He was 75. "John was a wonderful actor and a great friend to many," Aylward's agent Mitchell Stubbs said in a statement. Aylward also appeared in the dramedy series "Northern Exposure," as well as films "Seven Hours to Judgment" and "Teenage Mutant Ninja Turtles III." Head to the link in our bio for more on the life and career of John Aylward. 📸: Walter McBride, @gettyimages; @usatodaylife graphic.