Authorities say a man has died after exiting a moving truck on an I-5 ramp north of Vancouver, Washington, and was run over by the driver, who was his father.

Trooper Will Finn said both parents were in the front seat and the son was in the backseat Thursday morning while driving near Woodland. Finn says the son had some medical issues and got out of the truck after some kind of verbal altercation.

Finn says the father tried to slow down and move the truck to the shoulder but ended up running over his son. He died at the scene. The incident is under investigation.