Thorold Fire chief Terry Dixon says his staff acted exemplary in fighting Wednesdays blaze at the Star Choice Collision auto shop.
Evidence suggests the fire most likely started in a exhaust fan motor that somehow overheated or otherwise caught on fire.
"The workers tried putting it out with two fire extinguishers but it did not work. Within about four minutes the fire in the building was fully developed," said Dixon to Thorold News.
It took the crews about three hours to get the fire under control.
Two firefighters were sent home with heat exahustion, but no other injuries were reported during the incident.
