Three students were killed in a shooting at Oxford High School in Oxford, Michigan, on Tuesday, authorities said.They were a 16-year-old male student and two female students, ages 14 and 17, authorities said.Eight others were shot and injured, including a teacher, authorities said. They were transported to three different local hospitals. Two were in surgery and six in stable condition with varied gunshot wounds, Oakland County Undersheriff Mike McCabe said during a briefing Tuesday evening.