An inmate at the Oak Park Heights prison was severly injured after an assault by a younger prisoner, authorities said Tuesday.

The attack occurred over the noon hour Friday in the maximum security facility’s canteen area, according to the state Department of Corrections (DOC).

The victim, a 59-year-old man, was unresponsive and bleeding from the head when responding staff got to him, a DOC statement read. He was taken to Regions Hospital in St. Paul with “potentially life-threatening injuries,” the statement continued.

A 22-year-old inmate suspected in the attack was apprehended without incident and has been segregated from the rest of the prison population as the investigation continues. Charges have yet to be filed.

The DOC has yet to disclose the identities of either inmate or reveal what crimes they committed in connection with their incarceration. A motive for the assault remains under investigation.

Inmates work in the canteen filling orders for prisoners at all DOC facilities. Items for sale include snacks and other food, and personal hygiene and other items.

According to the DOC:

The younger inmate punched the other prisoner, and he hit his head while falling. The fallen inmate was then kicked in the head and face several times.

Additional DOC staff, including medical personnel, were dispatched to assist the victim and restore order in the facility, which can house up to 473 offenders.

The prison’s web page noted in red letters that visiting privileges were canceled the next day, but the notice did not explain why.

“While we make every effort to ensure a safe environment for both staff and those in our care, custody, and control, incidents such as this can start and end in a matter of seconds and have grave consequences,” said Corrections Commissioner Paul Schnell.