Firefighters are trying to determine what started a raging fire at a tire depot.

The fire broke out around 5 a.m. Tuesday at Centre du Pneu DMG on Lacordaire Blvd. in St. Leonard.

They were able to determine the fire began inside the building, on the side furthest from the street. They are still trying to figure out if the fire was accidental or if it was deliberately set.

About 30 firefighters battled flames for an hour to bring the fire under control before eventually extinguishing it.

Damage is estimated at $30,000 to the building, with an additional $20,000 loss of inventory.