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OCONOMOWOC, Wis. (AP) -- Authorities say more than 70 people were treated at local hospitals after an air quality issue forced the evacuation of Oconomowoc High School and the adjacent Oconomowoc Arts Center.
Western Lakes Fire District Chief Brad Bowen says low carbon monoxide readings were detected on some of the first patients treated, but officials could not immediately find a cause or source.
Superintendent Roger Rindo says Sliver Lake Intermediate students were rehearsing in the arts center for a concert when a number of young people became nauseated and light headed about 9:30 a.m. Thursday.
Officials say about 35 of the patients who were treated at hospitals were taken by ambulance.
Classes have been canceled for Friday, March 23, the district announced Thursday late afternoon. The district said families should check their emails for more information.