LINCOLN, Neb. (AP) — A 74-year-old inmate at the Nebraska State Penitentiary in Lincoln has died.

Lee Collins died around 8 p.m. Tuesday. Collins had been in prison since Dec. 11, 2014, on a four- to five-year sentence for fourth-offense DUI and driving on a revoked license.

A news release from state prison officials says Collins was being treated for an ongoing medical condition at the time of his death. Officials say the cause of death has not been determined.

State law requires a grand jury investigate into the death of any person in state custody.