Fire damaged the roof of the CN Rail locomotive repair shop on Industrial Way on Saturday.
Shortly after 3 a.m. fire fighters were called to the shop, and found smoke and flames coming from the roof.
While fire fighters located and attacked the fire, the incident commander directed CN staff to remove several locomotives from inside.
Hose lines from two fire engines were brought to the roof with a ladder truck, where fire fighters found an exhaust fan motor had caught fire.
Fire crews used power saws to cut open the roof around the fan to prevent the fire from spreading to the surrounding area.
Fire damage was limited to the exhaust fan and surrounding roof. Offices and washrooms below the fire suffered some water damage.
Fire fighters had the blaze under control in an hour. A subsequent investigation showed that carbon built up in the fan had caught fire.
The damage is estimated at $50,000 and no one was injured in the fire.
Over $5 million in property was saved, including the building and locomotives.