A Southland fire chief has described the scene of a crash between a car and a milk tanker, which went on to plough into a house, as the worst he has seen in almost 30 years in the fire service where anyone managed to walk away.

The car's driver died in the crash on State Highway 1 near Edendale about 10.20pm on Monday, but the truck's driver sustained only minor injuries and the five occupants of the house were unharmed.

The tanker collided with a car on the Edendale hill on SH1 before leaving the road, travelling through a paddock and hitting the house.

Police confirmed five people, including two children, were home at the time.

"The scene pretty much looked like a bomb had exploded, both with where the tanker had hit the corner of the house and obviously where the two vehicles impacted on the hill," Edendale chief fire officer Brent Shepherd said.

The car was travelling towards Invercargill, he said.

The Fonterra milk tanker was fully laden with 50 tonnes of milk as it approached the dairy giant's Edendale plant from the west.

"He's come over the brow of the hill and two vehicles have collided. They've been travelling in opposite directions," he said.

The tanker then left the road and went through a paddock before hitting a house beside the highway.

It was a miracle neither the truck's driver nor the occupants of the house were seriously harmed, Shepherd said.

"It just shows how lucky they were, I said to both lots of people that they probably need to look at buying a Lotto ticket because luck was on their side last night."

Other truckies and motorists stopped to help those involved in the car and to make sure no one was collided with at the scene as it was pitch black and raining, Shepherd said.

It was too early to know what caused the crash and Fonterra and police were investigating.

Six fatal crashes had occurred on the stretch of State Highway 1 between Edendale and Dacre in the past 20 years.

"There's certainly a lot of cars that run off the road ... a lot of fatal crashes," Shepherd said.

"Whether it's you know, people are getting tired ending their journey - you know, they've had a big night on the road or not - but it's just one of those roads and areas that there's always a lot happening."

Southland District Council Waihopai Toetoe ward councillor Paul Duffy, who lived in Edendale, said the highway was the scene of many crashes and it was unclear why.

"It just seems to be that vehicles do come to grief and unless you're close to it, the reasons can be very hard to fathom," Duffy said.

Last night's tragedy had resonated around the small community and many would be affected by the trauma, he said.

Published with permission