reporter: students were wag for waiting for the morning bell to ring and then shots fired.for waiting for bell to ring and then shots fired. waiting for the mornin to ring and then shots fired.wa ring and then shots fired. people started running and screaming so i started running and we heard another gunshot. the kid started getting mad and he pulled out a gun and shoots my friend. reporter: the shooter, a 13-year-old student, allegedly using his parents gun, wounded two fellow students. a teacher rushed to their aid. he walked up to a teacher and says, back up. the teacher started backing up. he pulled the trigger. the teacher was trying to make him put it down but he took the shot right then and there. reporter: a shot that killed 45-year-old michael landsberry, a popular eighth grade teacher. a former marine who served several tours in afghanistan and is now being called a hero. he was a very well-liked teacher by the students and other teachers. it s very un