They identified the victim as an 18-year-old woman and a 24-year-old man, both Swiss nationals and both passengers in the bus. Three other bus passengers and the two occupants of the car that was traveling behind the bus were injured and were taken to hospitals in Aarau and Baden.
The drivers of the truck and bus and two other bus passengers were uninjured.
The crash occurred on the road between the towns of Endingen and Lengnau in Aargau canton (state). Swiss postal buses combine delivering mail and carrying passengers in remote areas.