The driver of the truck which T-boned a car that drove through a stop sign at 80km/h said he didn't even have time to hit the brakes.
The Ford Focus rolled through a fence before it ended up on its roof in a garden, while the Hamilton-bound truck was spun 270 degrees.
The collision on Morrinsville Rd in Newstead, 8km east of Hamilton, happened just before 9am yesterday.
The elderly woman driver of the silver Ford Focus, who the Herald understands is from Mt Maunganui, died at the scene.
Tyre Shredding Waikato manager Rohan Cobb was driving back from a job in Morrinsville with workmate Shane Cochrane when he saw the vehicle straight in front of their truck.
The car had taken him by surprise by driving straight through the stop sign at the Ruakura and Morrinsville Rd intersection.
"I looked to the right and I saw a vehicle coming out of Ruakura Rd and didn't take much notice - then I looked ahead - and next minute that car was in front of me."
He believed the vehicle was travelling at 80km/h.
"To be honest I don't think I hit the brakes. I said 'bleep bleep' and the next 20 seconds or so I don't know what happened," the truck driver of 30 years said.
Mr Cochrane checked that Mr Cobb - who had been trapped in the truck and briefly blacked out - was alive, and then rushed to assist the woman, whose car had landed 10 metres away from the truck.
"He jumped through the front window that had popped out to check on the person in the car and I think it hit him pretty late just how bad it was," Mr Cobb said.
Both men walked away with a few cuts and bruises and and were taking a few days off to recover from the shock before returning to work.
Mr Cobb hoped to attend the funeral of the woman driver and meet her family. "Whether she had a heart attack or whatever ... But this car was going fast when we hit it."
Mr Cobb had given up driving trucks long distances about 10 years ago after witnessing some shocking accidents. The latest accident had made him rethink his profession again.
Owen Brown of OMS International, a Christian mission centre on Morrinsville Rd, said he had just arrived at work when the accident happened.
He and his wife Avalon ran to help the woman, whose car was stuck in a small garden in the front of their property.
"But there was obviously nothing that we could do," he said.
Both Mr Brown and another witness, Rob, said the intersection where the accident happened was notorious for near-misses and accidents.
"It's a terrible, terrible corner," said Mr Brown.
"It's very hard to see anything, especially for the traffic coming off Ruakura Rd."
The Waikato police serious crash unit is investigating the accident and the woman's death has been referred to the coroner.
The fatality, combined with the deaths of Rachel Wallace and her 3-year-old son Lochie on Friday, takes the Waikato road toll to 47 this year.
Meanwhile, a 58-year-old Te Puke man is dead after the BMW convertible he was driving crashed into a culvert, hit a concrete pole and flipped upside down on Sunday night.
The man was killed instantly inside the vehicle when it landed on a private driveway near the intersection of Gulliver Rd and SH2, east of Te Puke at 7.38pm.
A police crash analyst had attended the scene and an investigation was continuing, with the cause of the crash yet to be established.
Sergeant Mike Owen of the Western Bay of Plenty road policing unit said police would like anyone who saw the red BMW about the time of the crash to contact the Tauranga South police station.