(CNN)Authorities are searching for three teens who escaped from a youth correctional facility in Oregon on Sunday.
The teens assaulted a staff member and took their keys before leaving through a hole in the fence surrounding MacLaren Youth Correctional Facility, Oregon Youth Authority spokesperson Sarah Evans told CNN.
The teens, identified as Preston Andrizzi, 19, Anthony Fitz-Henry, 18, and Christian Goin, 17, lived in the same unit, Evans said. They are considered a safety risk to themselves and others, she said.
The staff member who was assaulted was released from the hospital, Evans said, and is in contact with authorities as state and local law enforcement agencies continue with the search.
This is the first escape from the facility since perimeter fencing was installed around 2000, Evans told CNN. Staff members at the facility do not carry guns or weapons, Evans said.
While Evans said the escape appears to be a planned event, authorities cannot yet speak to the youth's behavior leading up to their escape.
"Meetings started yesterday to review the incident to talk about what might have led to (it) to make sure we're following all the right procedures for safety and security," Evans said. "If any of them need to change, we'll also look at that too."
The facility remained on lockdown Monday while authorities met to determine when it will be safe for the youth to move around the campus.
The MacLaren Youth Correctional Facility is located between Portland and Salem.