A teacher’s intervention and an armed parent’s response ended Thursday’s shooting at Silver Rail Elementary School in Bend, Oregon, authorities said Friday. The attack killed three children and one adult, while a student and another teacher suffered serious injuries.

Bend Police Chief Mike Krantz said the 16 year old gunman, a former student at the school, entered the campus by climbing over a fence after throwing his firearm over it. The teenager was no longer enrolled in the Bend-La Pine school district.

The driver of a red truck on a nearby street saw the teenager and confronted him from inside the vehicle. The teenager fired at the truck and struck it at least three times, according to Krantz.

A 36 year old father of two students at the school witnessed the gunfire while driving nearby. The parent drove into the campus parking lot, then followed the teenager into the school building.

The assailant forced his way through external double doors by firing several rounds into their glass panes. He then entered a special education classroom and fired as many as 15 rounds, Krantz said.

A teacher confronted the gunman, threw her cellphone at him and wrestled with him for control of the firearm. She was not injured during the struggle, and Krantz said, “She almost certainly helped prevent more bloodshed.”

The parent had a legally secured .40 caliber pistol inside his vehicle and brought it with him while pursuing the gunman. When he entered the school, he saw the teacher confronting the teenager, and her intervention allowed the parent to fatally shoot him, Krantz said.

Responding officers found a Maverick 88 pump action 12 gauge shotgun and a backpack near the gunman. Investigators also found approximately 44 remaining rounds of 12 gauge ammunition either on the teenager or inside his backpack.

Authorities identified two of those killed as Rhoam Summer, a 5 year old student, and Meghan Lambert, a 25 year old teacher. Lambert was in her first year teaching at Silver Rail Elementary School.

The families of the other two victims, who were 8 and 11, declined to release their names and requested privacy. A 7 year old girl received lifesaving treatment inside the classroom and remained in serious but stable condition.

A 54 year old female teacher also suffered serious injuries that were not considered life threatening and was receiving treatment at St. Charles Bend hospital. The parent who shot the attacker was identified as Kaylub Giamanco by NBC News and The New York Times.

Giamanco is the father of two girls who attend the school. His mother, Kenda Freeman, said her son is not “seeking recognition but instead wishes to express his gratitude to the first responders, school personnel and community for the outpouring of love and support.”

Police identified the gunman as Griffin J. John II, 16. Krantz said John had previously attended Silver Rail Elementary School as a special education student but was not enrolled in the district when the shooting occurred.

“I don’t think we can underestimate or underappreciate that courage,” Krantz said of the teacher and Giamanco. He added, “The quick thinking to observe, to then park and follow someone into the school is incredible and undoubtedly saved people.”

Krantz called the teacher’s actions true heroism and praised her willingness to fight for the children around her. President Donald Trump also praised Giamanco on Friday, calling him a “great hero” for confronting the attacker.

“There was a great hero,” Trump told reporters. “He took care of business, and thank God we had him,” Trump said. “Otherwise, it would have been much worse. It’s a terrible thing, but thank goodness for a man that had a gun and knew how to use it.”

Lambert’s family said she had wanted to become an educator and teach in the district where she grew up. “She always fought for the underdog and those with special needs,” the family said, describing her as funny, opinionated and someone who lit up the room.

“Meghan loved those children and so we will show you love for her,” the family said. Their tribute remembered Lambert as an incredible sister, daughter, niece and granddaughter whose friends became part of her family.