10 students and 1 adult at Wentworth School in Scarborough were taken to local hospitals after they reported feeling ill Thursday morning.
The school was evacuated around 11 a.m., with students who were setting up for a concert in the cafeteria feeling sick. The school says one student passed out, with others experiencing respiratory symptoms or nausea.
Students were moved to Scarborough High School while crews went through the building but had returned to Wentworth by noon.
Fire Chief Richard Kindelan says the building was checked for gas leaks by two fire departments, and that they felt comfortable allowing students to return.
Kindelan says there were no injuries, with only minor or precautionary treatments for students who felt sick.
The fire department issued a statement saying the school is looking into whether the temperature on the stage and limited ventilation may have contributed to students’ symptoms.
An investigation into the incident is ongoing.