The North Carolina Department of Public Safety tweeted around 4 p.m. that the endeavored escape occurred at the Pasquotank Correctional Institution in Elizabeth City.
Walker said several other prison workers were injured in the incident, which involved a fire set by inmates in the prison's specialty sewing plant. Authorities say an inmate there set a fire in a trash can, then beat Callahan with the fire extinguisher that she had brought to douse the flames.
35-year-old Correctional Officer Justin Smith and 50-year-old Correction Enterprises Manager Veronica Darden were the two officers killed.
The high-security prison has 896 male inmates, according to the Department of Public Safety.
The Elizabeth City- Pasquotank Public Schools said several schools had been placed on lockdown. A call was made to the Pasquotank County Sheriff's Office that there was a "possible escape of prisoners" at the Pasquotank Correctional Institute, WAVY-TV reported.
Prison workers did several counts after the fire and all 725 inmates were accounted for, Acree said. It is still not clear whether the employed inmates were responsible for the attempted prison-break.
Ten patients were taken to Sentara Albemarle Medical Center in Elizabeth City, an official with Sentara Healthcare said. Peter J. Sengenberger, a spokesman for Sentara, said information on their conditions would not be released until Friday.
The notice came as students at one of the facilities, Pasquotank High School, were just to be released for the day and after dismissal times for the elementary and middle schools, said Tammy Sawyer, a spokeswoman for Elizabeth City-Pasquotank Public Schools. After school events and athletics have been cancelled.