According to Johnston County Sheriff Steve Bizzell, the fire was the work of an inmate.
According to Bizzell, the inmate was trying to light something through a hole in a glass window. A fire started alongside the wall of the third floor, and fire officials were notified and deputies were called in in case an evacuation was needed, but it was not.
Three investigators are now investigating the incident and trying to find which inmate started the small blaze. They say he will later face charges.
The Smithfield Fire Department was also called, and quickly extinguished the fire and found very minor damage.
Smoking at the jail was eliminated last year, according to Bizzell, and is not tolerated in any way.