Two dead, seven injured in crash involving truck and three cars in Wattle Flat, South Australia

Two women have died, and seven others have been injured — some critically — following a horrific smash on South Australia’s Fleurieu Peninsula.

A truck and three cars — a black Ford sedan, a silver Ford sedan and a white ute — were involved in the crash chaos on Main South Rd at Wattle Flat, 70km south of Adelaide, just after midday on Monday.

WATCH THE VIDEO ABOVE: Truckie charged over fatal multi-vehicle crash.

The truckie, a relief driver for the Fleurieu Regional Waste, was returning to Adelaide after collecting rubbish from the local tip.

Two Queensland women who were rear passengers in the silver Ford both died of their injuries.

A 44-year-old woman died at the scene while the second woman, 64, died later in hospital.

Seven others were injured in the crash, some critically, and have been taken to Flinders Medical Centre.

Floral tributes have been laid at the scene.

The driver of the silver Ford, a 43-year-old man, was taken to hospital in a critical condition while a fourth passenger — a 14-year-old boy — suffered minor injuries.

The driver of the ute, a 48-year-old man, was taken to hospital in a serious condition while the driver of the black Ford, a 38-year-old woman, and her two passengers, a 45-year-old man and a 10-year-old girl, were all taken to hospital with non-life-threatening injuries.

Local resident Peter Demourtzidis said he was “in shock”.

“I hate seeing people dying. You want to cry,” he said.

The driver of the truck, a 35-year-old Victor Harbor man, was taken to hospital with minor injuries and later arrested by investigators.

He has since been charged with two counts of causing death by dangerous driving, two counts of causing serious harm by dangerous driving and four counts of causing harm by dangerous driving.

The accused was out on bail on Tuesday.

Fleurieu Regional Waste is assisting police with the investigation and told 7NEWS their thoughts are with those involved in the crash and their families.

Major Crash officers spent Monday afternoon at the scene, trying to establish what triggered the nightmare crash.

A 10km stretch of road was closed to all traffic between Pyne Hill Rd and Forktree Rd in Myponga.

Diversions were in place and police asked motorists to “please avoid the area”.

Transport Minister Tom Koutsantonis said “the road is safe”.

“We are making it better by putting overtaking lanes,” he said.

The crash came a day after a dashcam captured a close call between a truck and oncoming traffic on the same stretch of road.

The truck, carrying sheep, pulled into traffic after trying to avoid a collision with a four-wheel-drive that was forced to slow down for a cyclist.