CLACKAMAS, Ore. - Three semi trucks and three cars parked at a Clackamas industrial area burned early Wednesday morning.
Clackamas fire investigators ruled the fire arson.
It happened on RAM Express property near 117th and Jennifer Street, south of Highway 224, at around 3 a.m.
Parts of three semi trucks melted in the fire. Two cars and a truck also burned. The fire did not spread to any buildings, firefighters said.
No one was hurt.
Firefighters said someone saw the fire and called 911. Flames were 40 feet high when crews arrived.
Damage was estimated at $250,000.
Oregon State Police and the Clackamas County Sheriff's Office have joined the investigation.
Anyone with information about the fire is asked to call 503-742-2660.