A fire broke out Sunday afternoon at Guerin College Preparatory High School in River Grove, which closed nearly a year ago and is set to be demolished. River Grove Fire Chief Sean Flynn said at 4:09 p.m., firefighters responded for smoke coming from the roof of the empty school building at 8001 W. Belmont Ave. in the western suburb. They found a small fire in the Holy Cross Gym at the school and put it out. The cause was under investigation late Sunday. They found a small fire in the Holy Cross Gym at the school and put it out. The cause was under investigation late Sunday. Flynn said the school is vacant and no demolition work is happening at the moment.