Connecticut authorities are investigating after an inmate, originally from Atlanta, died in one of their prisons this weekend.

About 11 a.m. Sunday, health services staff at Garner Correctional Institution discovered Jallen Jones required treatment and enhanced supervision in the prison’s in-patient mental health unit (IPM), the Connecticut Department of Corrections said in a statement.

As the 31-year-old was escorted into the IPM unit, officials say he became combative and then non-responsive. He was taken to a community hospital, where he was declared dead just before 12:30 p.m.

“The death of an individual under the care and custody of the Department of Correction is a very serious matter and we are fully committed to cooperating with external law enforcement,” corrections department Commissioner Scott Semple said in a statement. “There are no immediate indications suggesting that excessive force was utilized. However, we are in the infancy stage of an active investigation and will respond swiftly and accordingly to any determinations contrary to the initial findings presented.”

Jones was serving a 10-year sentence for a September 2014 armed robbery. The exact cause of death has not been released.

In other news:

Stormy Daniels Speaks About Alleged Trump Affair In "60 Minutes" Interview