Nebraska State Pen. inmate dies at 91

LINCOLN, Neb. -- An inmate in his 90's died on Saturday in Lincoln at the Nebraska State Penitentiary. 

91-year-old Clyde Hicks was serving a 15 to 20-year sentence for first-degree sexual assault on a child out of Hall County. 

Officials said his sentence began on September 15th, 2016. 

The cause of death has not yet been determined. 

The Nebraska Department of Correctional Services said that whenever an inmate dies in the custody of the NDCS, an investigation will be conducted by a grand jury.