Boxer Mike Tyson's 4-year-old daughter is on life support after she was found with her neck on a treadmill cable Monday, police said. The girl's 7-year-old brother found her on a treadmill with her neck on a cable attached to the exercise machine at their Phoenix home, police Sgt. Andy Hill said, calling it a "tragic accident." The boy told the girl's mother, who was in another room.