Saskatoon police and firefighters battled a structure fire in the 1900 block of Saskatchewan Avenue. Chad Leroux/CTV Saskatoon

Investigators have estimated a fire at a maintenance garage in the 1900 block of Saskatchewan Avenue caused over $1 million in damage.

There were eight semi-trucks inside the building, according to an update from Saskatoon Fire Department.

Firefighters were called to the garage just before 1 p.m. on Sunday after smoke was seen coming from the roof of the building.

Firefighters were able to extinguish the fire, but crews remained until 11:30 p.m. searching for hot spots, the department said in its update.

Firefighters were again called to the building at 7:50 a.m. after smoke was again seen coming from the buidling.

Fire investigators are still working to determine the cause of the blaze which appears to have originated inside the engine compartment of a semi-truck.