Sergeant Mary K. Ricard, 55, died in the line of duty after an incident at the Arkansas Valley Correctional Facility. She had been with the Department of Corrections for over eight years.
The events leading to the death of Ricard have not been disclosed. Sgt. Lori Gann also was injured and was listed in critical condition at a hospital in Pueblo.
Prison officials say there was an assault involving an inmate while breakfast was being prepared at the Arkansas Valley Correctional Facility in Crowley.
9NEWS has confirmed with a number of different sources that both women were cut with an object.
The Colorado Office of Inspector General and the Colorado Bureau of Investigation are investigating.
(KUSA-TV © 2012 Multimedia Holdings Corporation with The Associated Press)