The cause of a horrific smash that claimed four lives - including a young child - just north of Taupō in 2017 can now be revealed.
Newly released coroner's findings show that fatigue by one of the drivers was the contributory cause of a multiple-fatality crash near Taupō on October 10, 2017.
Helena Adele Paul, aged 56 of Kaikohe, had been visiting Hawke's Bay with her friend, Leighton Phillip Ahuriri, 60. Her grandsons Hone Te Ahurei Kanuta-Hawkins, 5, and Kaydentz Kanuta, 1, were in the back seats.
The finding by Coroner Gordon Matenga says that about 3.15pm Paul was driving her black Nissan Lafesta north on State Highway 1 near Taupō.
At the same time, a Toyota Alphard people mover driven by Tiateima Launoa with seven passengers was travelling south from Auckland to Palmerston North. The people mover had three rows of seats. Mele Ilisapesi Oliveti, 43, also known as Pesi Tuivai, was in the rear right seat behind the driver.
About 23km north of Taupō, Paul became fatigued and lost awareness of her position on the road, allowing the Nissan to drift across the centreline and into the southbound traffic lane.
Launoa, seeing the oncoming car, moved to the right to try to avoid a collision. At the same time Paul became aware of where she was and steered left. Both vehicles collided in the southbound lane. Paul, Ahuriri, Hone Kanuta-Hawkins and Mele Oliveti all died at the scene.
The coroner's finding states that Paul being fatigued was a contributory cause of the crash and of all the deaths.
Unrestrained passengers and child restraint seats (two children in child seats in the back of the people mover were buckled into the seats, but the seats were not secured by seat belts or anchor points) and loose luggage were contributing factors in the death of Mele Oliveti.
Paul, Ahuriri and her grandsons had been in Napier for three days to celebrate a birthday and left on October 10 intending to travel to Auckland. Paul was driving and Ahuriri was in the front passenger seat. Hone was on a booster seat in the left rear, wearing a seatbelt. At some stage, he moved his left arm over the top of the diagonal shoulder strap. Kaydentz was properly secured in a child restraint seat behind the driver.
A witness travelling behind Paul's Nissan said he had followed it for about 20 minutes and that at first the vehicle kept speeding up and slowing down but settled to a more consistent speed so he sat behind it at a safe distance. He saw the Nissan drift across the centre line as if the driver was asleep. It ended up completely on the opposite side of the road, still travelling at about 100km/h. The people mover came up the road in the opposite lane.
"The black car [the Nissan] was completely in the southern lane heading into the path of the larger people mover. It seemed then that the driver of the black car woke up because the black car then evasively swerved to [sic] back to the left attempting to get back into its lane.
"I watched as the larger people mover attempted to swerve to their right to avoid a collision with the black car. I watched as the black car crashed pretty much head on with the larger people mover."
Launoa, driving the people mover, said he got a shock when the Nissan crossed into his lane.
"He was going straight. I was confused what to do so I went to the middle. The other car has then tried to go back into their lane but it was too close. I moved the steering wheel to the left but it was too close and that's when we hit."
Coroner Matenga found according to the evidence that Paul succumbed to fatigue; speeding up and slowing down for no apparent reason, then drifting across the centre line.
"These movements are consistent with a driver who has become unaware of their position on the road and the approaching danger of an oncoming vehicle. I agree with [crash investigator] Senior Constable Mitchell-Ellis that fatigue has been the cause of the loss of awareness and loss of control which led to the head-on collision," the coroner said.
"Mr Launoa was in an impossible position."
Post-mortem examinations showed Paul died from multiple severe injuries, Ahuriri most likely died from severe head injuries and Hone Kanuta-Hawkins from brain and neck injuries.
Mele Oliveti died at the scene from severe injuries to the neck, chest and abdomen. Two child restraint seats, which had not been properly anchored, luggage and unrestrained passengers were propelled forward in the crash and this caused Oliveti's seat to fold over, contributing to her injuries.
Taupō road policing manager Senior Sergeant Fane Troy, who attended the scene, said fatigue was a factor in a lot of crashes but unlike drugs or alcohol, there was no way of measuring it after a crash.
He said where the crash occurred was two-and-a-half to three hours drive from Napier and research showed that after two hours of travel drivers needed to stop, have a break and refresh themselves.
Because Taupō was two or more hours from places such as Auckland, Hamilton and Napier there were a lot of crashes in the district where fatigue could have been a factor, Troy said.
"One of the classic signs is a person who weaves within their lane, crosses the fog line or centre line or erratic speed, the same characteristics of an impaired driver on drugs or alcohol.
"We get a lot of calls from people who think they are following a drunk or drugged driver and when we stop them, we find that they are fatigued."
Troy said it was known that Helena Paul had had minimal sleep in the lead-up to the crash and family members had said she looked tired.
Most fatigue-related crashes occurred between midnight and 8am, or 2pm to 5pm on straight segments of road. This accident occurred at 3.15pm.
In relation to loose items and unrestrained passengers, Troy said seatbelts saved lives.
"Everybody needs to be restrained in the vehicle. If you have got luggage or anything in the vehicle, in a crash at 100km/h you can be killed by it. We've been to numerous crashes over the years caused by passengers in the back not being restrained and coming forward; or luggage coming through and causing non-survivable injuries to people in the front."
He said one of the most dangerous things he regularly saw while driving was people with dogs loose in their cars or on their laps.
"A two or three kilogram dog, if that hits you in the back of the head at 100km/h it could easily break your neck."
The joint coroner's inquiry into all the deaths was held as a hearing on the papers, a finding on the written evidence instead of at an inquest, in 2018 but was publicly released only this month after an Official Information Act request.
Susan Kanuta, the daughter of Helena Paul and mother of Hone Te Ahurei Kanuta-Hawkins, and her twin sister have both spoken of their pain and loss. Susan lost both her mother and eldest son and her youngest son Kaydentz, now 4, was critically injured.
"Our mother, sister, aunty, cousin, nana was one of those straight-up ones who would growl if she had to give orders but she always had that heart of love and always showed everyone how much she really loved them," Susan wrote of Helena Paul.
"When we lost her and my son it was one of the most heartbreaking moments ever to have to go through. I was so numb and lost for words, I was just staring into the darkness thinking this cannot be true, however it was. We lost four important people that afternoon and my youngest son was very critical. Life has never been the same since.
"Kaydentz still has some minor problems here and there and last week we found out something very sad was happening with my baby, however I'm grateful to have such a great family who still support me 100 per cent.
"It's been almost three heartbreaking years since that moment and we, the children to Helena Paul and mother to Hone Kanuta-Hawkins, give our deepest condolences to Mele Oliveti's family and Leighton Ahuriri's family."
Susan Kanuta's twin sister, Angela Kanuta, said life had not been the same since the loss of her mother and nephew.
"Still to this day I wait patiently for the return of our mother and baby. The last words I heard from my mother and baby were 'we love yous and we will see yous when we return home safely', but that never happened."
Leighton Ahuriri's family said their father was taken from them "so quickly and tragically".
"He is dearly missed every day and he never is too far away from the thoughts of his children that he leaves behind. His three daughters and beautiful grandchildren continue to strive forward making the greatest of achievements in this tumultuous climate. He would be so proud that in the face of unbearable uncertainty, his children and grandchildren have persevered. We love and miss you so much Dad."
Mele Oliveti's family could not be contacted for comment.
The 19-year-old disappeared without her wallet or mobile phone.