The man, 42, lost control of his B-double and crashed into a former service station site, which was being used as a home and business, shortly before 3pm. 

The vehicle ploughed into the front bedroom where a couple was sleeping. 

A 45-year-old woman from Queensland was inside the cabin and was cut from the wreckage before being taken to hospital.

A 67-year-old local woman, who was inside the premises, was also injured.

Both were later flown to Adelaide by the Royal Flying Doctor Service with serious injuries.

The service road where the crash occurred is a 50km/h stretch on the outskirts of the township, alongside the Dukes Highway. The truck was heading into Bordertown from Adelaide.

Locals, including Tatiara Council chief executive Robert Harkness, stopped by the crash scene on Thursday morning.

"As police continue to investigate the circumstances of this fatal truck crash, we are keen to hear from anyone who may have seen the truck immediately before the crash or the crash itself," a police spokesman said.

Information can be supplied to police by phoning Crime Stoppers 1800 333 000 or online www.sa.crimestoppers.com.au.

- Border Chronicle