OAK PARK HEIGHTS — A correctional officer has died after helping respond to an inmate’s attack on an officer at Oak Park Heights prison.

The Minnesota Department of Corrections said 37-year-old Officer Joseph Parise died after suffering a medical emergency while on duty Monday.

The department said an inmate assaulted an officer at the maximum-security prison around noon. Other officers and staff, including Parise, responded. Two of the responding staff members were hurt, and were evaluated and released.

Parise, a four-year veteran, returned to his post and suffered the medical emergency. The department said he was taken to Regions Hospital in St. Paul, where he died.

An investigation is underway. Oak Park Heights prison is on lockdown.

In July, authorities said a convicted killer beat a correctional officer to death at Stillwater state prison.