The terrifying moment a freight train smashes into a truck on a level crossing has been captured on video by a couple who witnessed the crash.

Two were injured when the train collided into the vehicle stuck on the tracks in the US state of Louisiana, Yahoo is reporting.

A train conductor was seriously hurt and an engineer suffered minor injuries when the freight train collided with the truck, derailing two engines and 17 cars, according to Yahoo.

The incident was captured on film by a couple sitting in a car close to the crossing in in Mer Rouge, Louisiana.

Scroll down to watch the video.

"He's stuck, I think," a man says over footage of the truck stranded on the tracks.

"Holy mother of moo moo," says a woman in the car as the train collides with the truck.

"Oh my God, tell me he got out, just tell me he got out," she says of the driver.

The conductor's injuries were not considered life-threatening, a Union Pacific spokesman told Yahoo.

He said the conductor was airlifted to a hospital 150km away from the incident and the engineer was taken to a local hospital.