A furnace motor malfunctioned, causing smoke to fill one of the building’s rooms, according to Sheffield-Sheffield Lake Schools Superintendent Will Folger.
Crews were called about 8:15 a.m. and arrived to find staff had evacuated the building. Firefighters reported a little before 8:30 that they had the situation under control and were ventilating the building’s library.
According to the district’s Web site, students aren’t allowed in the building until 8:30 a.m., and school starts at 8:50 a.m. Students in preschool through first grade attend Knollwood.
Crews got the OK to begin letting students into classrooms about 9:10 a.m.