Updated: 02/06/2014 9:06 PM
Created: 02/06/2014 1:06 PM KSTP.com
By: Megan Stewart
A suspected carbon monoxide leak has forced an evacuation at a southern Minnesota school and sent nearly 30 people to the hospital.
Police were called to Springfield Public School just after 9:30 a.m. Thursday after a couple of students reportedly fell ill in the school auditorium while rehearsing for a school play, with two kids passing out and others vomiting.
The entire school was evacuated. By midday, 30 children, fourth and fifth graders at the school, were taken to the Mayo Clinic Health Center in Springfield. Some underwent an oxygen treatment, according to a health official.
Students and staff were taken to the Springfield Community Center, where students were to be picked up by parents.
The Springfield Fire Department and a crew from CenterPoint Energy were checking the building to make sure all students were out, and to find the source of the leak.
According to the school's superintendent, officials did not find carbon monoxide.
According to a health official at Mayo, the symptoms were very consistent with carbon monoxide poisoning. Fingers probes on students showed higher CO levels.
On Friday, officials will go back to the school and retest for carbon monoxide because they opened school doors following the incident.
Crews from the school and CenterPoint Energy are looking into the situation.
The Associated Press contributed to this report.