Detectives are piecing together what caused a fatal crash in Annadale on Friday 7 June.
Police and emergency services were called to the Sturt Highway at the intersection of Diagonal Road around 2.15pm after a car and a truck collided.
A 74-year-old Riverland man died at the scene and his 30-year-old passenger was airlifted to hospital in a serious but stable condition.
The two people travelling in the truck we not physically injured.
The incident brought the State’s Road Toll to 54 compared with 35 at the same time last year.