Tinley Park, IL- Rescue personnel responding to reports of a carbon monoxide leak at a KinderCare in Tinley Park detected ahigh level of CO Thursday evening, according to reports.

Firefighters arrived at the early childhood education center on 175th Street and 80th Avenue around 5 p.m. Thursday. Students and teachers reported getting sick, likely from carbon monoxide poisoning. Crews eventually detected a CO level of 210 ppm.

Information provided by the U.S. Consumer Product Safety Commission on the effects of carbon monoxide says exposure at concentrations between 150 and 200 ppm can cause disorientation or unconsciousness, and can become life-threatening after a long period of exposure.

The accredited KinderCare location in Tinley Park works with infants, toddlers, and kids of up to 12 years old, servicing nearby schools including John A. Bannes, Fernway Park, Helen Keller, Millenium, Christa McCauliffe, Fulton and Memorial.

It’s not clear yet how many children and teachers were affected by the carbon monoxide. Several ambulances remain on the scene Thursday evening.