The sound of tyres skidding on the highway and the impact of a van colliding with a car is something Jeremy Reuben will never forget.
The Timaru man was travelling along State Highway 1 between Timaru and Ashburton on Wednesday afternoon, with his partner and their two children, when a horrific crash unfolded in front of them.
The crash claimed the life of 80-year-old Geraldine woman Ann Margaret Jones.
Reuben was travelling north when a car in front of him pulled to the side of the highway.
He said it looked like Jones [the driver] then tried to make a u-turn but an approaching van collided with her vehicle.
"We were the first car behind the van that crashed into her, so it happened right in front of us," he said.
"The noise - the tyres, the smash of the car - was so loud."
For a moment he feared an oncoming truck was also going to be caught up in the collision.
"I thought a truck coming from the other direction was going to go straight through the middle of them, but he locked up and there was a cloud of smoke for about 60m.
"It was horrific. As soon as the van hit her I knew it wasn't going to end well that's for sure."
Reuben said he veered his four-wheel-drive on to the grass and "flew out of the truck" to try and help.
"I got my partner to ring the ambulance straight away," he said.
He said there were about seven people trying to help while he climbed through the window of the badly damaged car.
"I just went with my instinct and tried to do anything I could."
Inside he found Jones and a male passenger, believed to be her son.
"I was talking to him the whole time and making sure he was all right.
"He told me she had just picked him up from the hospital.
"I felt quite helpless, which was not a good feeling."
Jones and the male passenger were transported by ambulance to Timaru Hospital's emergency department, where she later died from her injuries.
Reuben said he only found out Jones had died from reading it online.
"It made me feel pretty s***. I thought if I could go back then I would have tried something else.
"I didn't sleep until last night. It has affected me a wee bit because I keep wondering whether we could have done more.
"I have buried a lot of people, but that bloody got to me. I can't un-see that."
Reuben wants to know how the male passenger is doing.
"We haven't been able to get in touch with family but we were trying to find out whether the son was still in hospital," he said.
"I want to take him some flowers."
A police spokeswoman said the crash was still being investigated and Jones' death has been referred to the coroner.