Complex sentence: There were few casualties, and the war came to a sudden end: when a vehicle carrying Stevens'son burst through a Papua New Guinean roadblock in late August 1980, the soldiers opened fire on the vehicle, killing Stevens' son.
Split into simpler sentences: There were few casualties, and the war came to a sudden end. When a vehicle carrying Stevens'son burst through a Papua New Guinean roadblock in late August 1980, the soldiers opened fire on the vehicle, killing Stevens' son.