BUTTE, Mont. (AP) - The Montana Highway Patrol says two people were killed and one was seriously injured when a pickup truck pulling a trailer jackknifed and fell off a bridge.

Trooper Tammy Perkins says the Saturday morning crash killed 49-year-old driver Douglas Ray Jacobsen and his brother-in-law 45-year-old Richard Daniel Streissguth, both firefighters from Ridgefield, Wash. Another passenger, a 14-year-old boy, was critically injured.

Perkins says weather was a contributing factor to the crash, which happened when the Ford F-350 and trailer jackknifed and hit the guardrail.

She says the trailer pushed the truck off the bridge, which hung briefly before separating from the trailer and landing on its roof.

Clark County, Wash., fire officials say the men were on their way to Bozeman to pick up an antique fire engine.