Four people were killed in a school shooting in Oregon before a bystander “heroically” entered the school and killed the shooter.

A 16-year-old boy, identified by police as Griffin J. John II, armed with a Maverick 88 pump-action shotgun, entered Silver Rail Elementary School shortly before 1 p.m. Thursday local time, where he began opening fire at those inside. Bend Police Chief Mike Krantz identified the victims killed as a 5-year-old, an 8-year-old, an 11-year-old, and a teacher. Just minutes into the shooting, a local good Samaritan entered the school behind him, shooting and killing John.