MINNEAPOLIS (WCCO) — A corrections officer who rushed to help colleagues being attacked by a prisoner died Monday from a medical emergency, the Department of Corrections said.

The DOC says 37-year-old Joseph Parise had just finished responding to the attack at Oak Park Heights prison when the emergency happened.

He was taken to Regions Hospital, where he died Monday afternoon.

The prison is still on lockdown.

Members of the Department of Corrections made their way to Region’s Hospital after learning about the death of one of their own.

Parise worked as a correctional officer at the Oak Park Heights facility for four years.

The incident happened around noon in one of the housing units inside Oak Park Heights Correctional Facility. An inmate repeatedly punched a corrections officer in his face, and Officer Parise was one of several who ran to help, the DOC said.

After the inmate was contained, Parise returned to his post.

Parise was a United States Navy veteran who served on the Oak Park Heights Honor Guard.

He is described by his coworkers as a fun, charismatic and positive person — a very caring man who was always willing to help others.

The DOC is investigating the incident. Officer Parise’s cause of death has yet to be determined.

The American Federation of State, County and Municipal Employees — the union that represents officers at Oak Park Heights – said it offers its deepest respects to Parise for his courage and his service.

The union president says Parise was considering a transfer to Stillwater, where a corrections officer was killed in July. He thought he could better help his fellow correctional officers there by helping provide more staff.

Oak Park Heights correctional officers have created a GoFundMe to help Parise’s family.