A 16-year-old opened fire on Thursday at Silver Rail school in Bend, Oregon, killing three children and a teacher before being shot dead by an armed bystander, according to The Guardian.

The gunman, a Bend resident, forced his way in at around 1pm by shooting at locked doors. Authorities said the children killed were aged five, eight and 11, and that a seven-year-old child and a 54-year-old teacher were hospitalized in critical condition. Police identified the gunman as Griffin J. John II, a former pupil and a special educational needs student there, the British Broadcasting Corporation (BBC) reported.