The Bismarck Fire Department responded to a report of smoke at a storage building in Bismarck early Tuesday morning.
Crews searched the building and discovered that the source of the smoke was a fire in a work truck inside the unit and were able to extinguish the fire.
The fire caused significant damage to the box of the pickup and some smoke damage to the interior of the shop condo.
No one was injured.
The cause of the fire was accidental and appears to be from a spontaneous combustion of rags that had been used to apply lacquer to wood product.
The fire and smoke caused about $12,000 in damage.