The 15-year-old boy who shot himself after taking 23 students and a teacher hostage at his school in Wisconsin has died of his wounds. Marinette Police Chief Jeff Skorik said Samuel Hengel died yesterday at a hospital in Green Bay. Hengel shot himself with a handgun as police stormed a classroom at Marinette High School on Monday night after a stand-off lasting several hours. Chief Skorik said police are still trying to ascertain his motives.