Williamson County Sheriff Bennie Vick says there was a carbon monoxide issue Wednesday morning at the Williamson County Jail.
He says an inmate first complained of a headache at around 4 a.m. The inmate was treated at an area hospital and returned to the jail.
As the morning progressed, additional inmates and staff began to complain of headaches or dizziness. The Marion Fire Department conducted air quality tests, which determined there was carbon monoxide in part of the Jail.
A small number of inmates and staff were transported to area hospitals as a precaution.
Marion Fire Department and other fire departments have been on scene to ventilate the building. Ameren and engineers are also on scene to determine the source of the carbon monoxide.
Visitation at the jail is cancelled until further notice.
Court cases for inmates have also been affected and will have to be rescheduled.