Two tractor-trailers parked at Con-Way Freight on the 900 block of 4th Avenue North were consumed by flames Saturday afternoon.
The flames caused minor heat damage to two other tractor-trailers parked nearby.
The fire broke out at about 5 p.m., starting in the engine compartment of one tractor trailer and then spreading to three others parked nearby, according to a release from the Billings Fire Department.
It's estimated that the fire caused $350,000 worth of damage.
Both the property and contents were insured, the release stated.
The exact cause of the fire remains under investigation.
Nobody was hurt.