Three people have died after a head-on collision in South Australia's south-east this afternoon.
Police and emergency services were called to the Princes Highway at Suttontown, 5 kilometres west of Mount Gambier, at 12:30pm.
The three occupants of a Ford Territory — a 39-year-old woman, a 77-year-old woman and an 80-year-old man, all from Millicent — died at the scene.
Four occupants of the second car, a Toyota Landcruiser, were taken to hospital with non-life-threatening injuries, while a fifth is being treated for critical injuries.
Princes Highway is closed between Sassanowsky Road and Kangaroo Flat Road, with traffic diversions expected to remain for several hours.
Major crash investigators are currently at the scene.
Limestone Coast officer in charge Superintendent Phil Hoff said the fatal crash was "an absolute tragedy".
"You can see the road is clearly defined by barrier lines, and what's happened is two vehicles have collided on one side of the road," he said.
"That begs some questions, and our major crash people will put those pieces together."
He said it appeared one vehicle was travelling towards Mount Gambier, while the other was travelling towards Millicent — but investigators still needed to determine which was on the wrong side of the road.
He said the incident had "the worst possible outcome".
"Three people dead, here we are a month before Christmas," he said.
"In the Limestone Coast this year, we haven't had any lives lost on our road, none. In one fell swoop, three people have lost their lives and five others are being treated in hospital."
Superintendent Hoff said while the crash was "absolutely heartbreaking", it made him "angry" as well.
"We've gone to extraordinary lengths and been very vigorous in our traffic education campaigns, our traffic enforcement campaigns, and yet here we are," he said.
As South Australia lifts its coronavirus border restriction with Victoria on Tuesday, the regional border communities were anticipating "a lot more traffic on the road".
"The public can well and truly expect us to be out in force, ensuring that people are doing the right thing," Superintendent Hoff said.
"We've all gone through so much hardship this year, the last thing we need is something like this to occur again."
South Australia's road toll now stands at 85, compared to 101 at the same time last year.
