The Jarrettsville Volunteer Fire Company was alerted for two engines to respond to North Harford High School for a reported building fire. Engine 712 quickly responded followed by Engine 714. Both engines arrived with Whiteford Engine 611 with nothing evident. Crews went to work inside the evacuated school and investigated multiple areas including the boiler room. Crews were able to locate a malfunctioning fan motor on the roof of the school. Firefighters were able to secure the area and allowed students to re-enter the school. Units were placed in service soon after.