BEND, Oregon -- Four people are dead after a teenage gunman opened fire Thursday at Silver Rail Elementary School in Bend, Oregon, police have now officially confirmed. The victims are three children, ages 5, 8, and 11, and a teacher.

Two more victims remain in critical condition: a 7-year-old child and a 54-year-old teacher. The 16-year-old shooter forced his way into the building by shooting at the locked doors, police said. A bystander who was legally armed pursued the gunman into the school and shot and killed him; officers arrived three minutes later. Oregon Governor Tina Kotek publicly praised the bystander for his courage.

The shooter's identity and motive have not been released. Silver Rail Elementary serves kindergarten through fifth grade, with roughly 450 students. Families were directed to a reunification point at Journey Church on South Highway 97, where parents waited to embrace their children. The Bend-La Pine School District canceled all schools and activities for Friday. A vigil was held Thursday evening in Drake Park.

Bend police spokeswoman Sheila Miller said the investigation is continuing, with agents from the FBI's Portland office assisting. Bend-La Pine Schools Superintendent Steven Cook said the district was "stunned and heartbroken by this senseless tragedy," adding, "No words can adequately express the grief our community is experiencing." FBI Director Kash Patel said every needed resource would be made available.