A coroner's report into a fiery crash in Canterbury that killed three Singaporean students last year found driver fatigue was a likely cause.
Sherwin Chong Shi Yun, 21, Xinyue Yang, 21, and Jia Jun Vincent Lim, 24, were on a trip around New Zealand when their campervan crashed into a guard-rail after 1am on 17 April along State Highway 79's Geraldine-Fairle Highway and rolled.
Minutes later the van caught fire, and they were trapped inside and died.
Coroner Alexandra Cunninghame ruled the students died from the effects of inhalation of smoke and fumes in an enclosed space.
The investigation found it was highly likely they would have survived the crash had the van not caught fire.
A report examining the events of the fateful night has been released.
"At 1:03am on 17 April 2023 Xinyue made a 111 call. She told the dispatcher that she had been in an accident on the way to Geraldine, that she was a passenger in a campervan with two friends, and that her friend was "caught" and could not get out of the vehicle. She did not say which friend this was. 40 seconds into the call, Xinyue told the dispatcher that there was a fire. After this, screams and other noises could be heard, until the line went dead at about three minutes into the call," Cunninghame said.
Before the phone line went dead, emergency services had been dispatched to the scene and the first fire-fighters were there at 1.13am, she said.
"The van had rolled onto its driver's side and was engulfed in flames. Once the fire was extinguished, the first responders established that there was one person near the back of the van (by the roof) and two people in the front. One was in the driver's seat and the other had fallen towards the driver's seat when the van rolled. All three bodies were so badly burned that they could not be identified.
"After extensive inquiries, the bodies were identified. Sherwin was identified as the passenger in the rear of the van. Vincent was in the driver's seat, and Xinyue was the front passenger."
Post mortems were carried out on the bodies.
"The pathologists noted extensive charring on all three bodies... Sherwin and Xinyue did not have any life-threatening impact injuries. Vincent had a modest acute subdural haemorrhage and minor pulmonary contusions, but he did not have any 'fatal impact injuries'," the report said.
The blood of all three was negative for drugs and alcohol.
The report said the students were sightseeing around New Zealand before the crash.
Sherwin was studying at the University of Otago, Xinyue was studying at the University of Auckland, and Vincent was studying in Singapore.
"On 8 April 2023 Vincent arrived in New Zealand for a two-week holiday. Sherwin met him at Christchurch and the two collected a Toyota Hiace campervan. They drove to Auckland where they met Xinyue, and the three then travelled back down New Zealand. On 15 April 2023 the friends went skydiving at Wanaka. On 16 April 2023 at 11:40pm their campervan was captured on CCTV travelling through Lake Tekapo village."
Senior Constable Aaron Tapp investigated the crash. He reported that State Highway 79 was in good condition and was dry at the time of it.
He calculated that the van was travelling at no less than 91km/h when it struck the guard rail barrier, below the 100km/h speed limit. No evidence was found to suggest that the van had braked prior to the crash.
The van was tested, and no mechanical faults were found.
"It was established that the van's headlights had been on in the "half beam" position. SC Tapp's evidence is that a 'normal prudent driver' would have had their lights on high beam at the crash location, depending on traffic flow," the report said.
SC Tapp's opinion was that it was likely fatigue was a causative factor to the crash.
"He noted that the crash had occurred between midnight and 8am, which is considered a "biological risk factor" for fatigue. Further predictors that may infer fatigue were identified as the crash involving a single vehicle on a straight segment of road, and the van leaving the road at a shallow angle without taking emergency action (braking or correcting). He also noted that it was possible that the others in the vehicle may have been sleeping," Coroner Cunninghame said.
"The time of night when the crash occurred meant that it was possible that Vincent [the student believed to be the driver] had been awake for more than 12 hours."
Fire and Emergency specialist investigator Craig Chambers attended the scene and later examined the van.
He eliminated a gas or fuel leak as the cause of the fire.
"The van had a 'house battery' near the wheel arch. A house battery powers the living area of the van. Fire damage indicated that the fire started on or at floor level, in front of the wheel arch in the rear of the van and spread into the engine compartment. Mr Chambers' opinion was that the probable cause of the fire was an electrical arc which was created when the house battery was displaced as the van collided with the road," the report said.
"All of the doors of the van were closed when emergency services arrived. Due to damage from the fire, it was not possible to establish whether any of the doors were locked at the time of the crash."
Cunninghame said the evidence did not explain why none of the three victims were able to get out of the van after it crashed.
"Vincent may have been incapacitated by a head injury, but Xinyue was able to make a 111 call. It is possible that the doors were too difficult to open once the van had tipped onto its side."
It would not have been possible for an emergency vehicle to be on the scene in time to get anyone out of the van before it caught fire, or to stop the fire once it started, she said.
Cunninghame said this tragic accident illustrated the importance of not driving when fatigued,
"All drivers, and particularly those who are planning road trips around New Zealand, must ensure that their itineraries allow sufficient time for rest and sleep so that they are not driving tired.
"I extend my condolences to the families and friends of Sherwin, Vincent, and Xinyue."