The SA police force said that emergency services were called to reports that a small plane had collided with a hangar while trying to land at Parafield training airport, 15 km north of central Adelaide, around 2:10 p.m. local time on Wednesday, Xinhua reported.
Chief Inspector Andrew McCracken told reporters at the scene that the two occupants of the plane were killed in the collision.
He said that 10 other people who were inside the hangar at the time have been taken to hospital, including one in a life-threatening condition with significant burns and two more with serious injuries.
The Australian Broadcasting Corporation reported that a large number of student pilots were safely evacuated from the scene.
Firefighting authorities said the crash sparked a major fire exacerbated by fuel stored in the hangar.
The Australian Transport Safety Bureau said in a statement that the aircraft involved in the incident was a twin-engined Diamond DA42.
It said that it has deployed investigators who will arrive at the scene on Thursday and commence evidence-gathering activities, including recovering aircraft components for further examination and interviewing witnesses.