LINCOLN, Neb. (AP) — Authorities say an inmate who tried to escape from the Nebraska State Penitentiary was caught before he could climb over an internal fence.

The Department of Correctional Services says the unidentified prisoner tried to escape around 7:30 p.m. Saturday.

Officials say a tower officer fired a warning shot at the inmate. Corrections officers immediately responded to the fence and deployed chemical agents. The inmate continued to climb but staff members were able to remove him.

Corrections Director Scott Frakes says the inmate never breached the prison’s inner perimeter, and the public was never at risk. An investigation is under way, and the results will be forwarded to the county attorney.

The penitentiary is surrounded by two chain link fences topped with razor wire and a tower with armed officers.