Police say a teacher fought a 16-year-old gunman during a deadly shooting at Silver Rail Elementary School in Bend, Oregon, on Thursday. The attack killed three children and a teacher.

Authorities said the teacher tackled the shooter and threw her phone at him, potentially preventing further violence. A father whose two daughters attend the school then shot the suspect, police said.

The victims killed were aged 5, 8 and 11, along with a teacher. Another child, aged 7, and a 54-year-old teacher were hospitalized in critical condition.

Police identified the suspect as Griffin J. John II, a former student at the school. Investigators said he used a 12-gauge shotgun to shoot through locked doors and enter the building. Police Chief Mike Krantz said the suspect fired as many as 15 shots.

The first emergency call came shortly before 1 p.m., reporting that someone with a long gun had fired at a person outside the school. Additional calls followed from inside the building, and officers arrived within minutes.

Authorities are continuing to investigate the motive behind the shooting. Meanwhile, flowers, balloons and stuffed animals have been placed near the school as the community mourns the victims.