A packed tourist bus skidded to a halt just over a metre short of a cliff edge, in a horror South Island crash involving 36 people yesterday.
Seven patients remain in Christchurch Hospital, two in a critical condition and five serious, and five are in Greymouth Hospital with minor to moderate injuries, after a car and a tour bus collided in the Otira Gorge near Arthur's Pass.
The around 40-seater bus, carrying Asian tourists, rolled trapping one passenger beneath it.
"When we arrived the bus was, thank God, still on the road. There's not much outside of the road other than a straight drop to the bottom," St John's Kerry Mitchell said.
"If it had slid another metre and a half to the left [off the cliff], it would have been a very different job. The bus was on its side right at the very edge of the road, the barrier on that outside edge of the road had been blown out from the impact."
Mr Mitchell, a St John territory manager and the incident commander at the scene said the car was crushed against the hillside.
Its three occupants were also trapped in the vehicle, and needed to be removed by firefighters. Ambulance staff worked on the passengers while they were being removed.
"The car didn't look like a car anymore, it just looked like a mangled wreck. It was completely crushed, particularly in the front driver's-side area."
He described the scene as "horrific", one of the biggest jobs he'd ever attended.
"There were multi-trauma injuries, there were broken bones, there were some traumatic partial amputations, severe crush injuries for two of the patients that were trapped as well as head injuries and soft-tissue injuries."
Some patients with head injuries needed advanced medical treatment and were sedated to make them safe for transport, he said.
The road was covered in broken glass and leaking engine fluids and fuel. Cars were backed up for miles in both directions.
"There were members of the public mixed in with the patients and also emergency services arriving. It was organised chaos there for a few hours."
There is no cellphone reception in the area, and the Greymouth Star reported that a passing motorist was flagged down at the crash scene about 11am to seek help.
The person then travelled to nearby Arthur's Pass village, where the accident was reported to emergency services. Four helicopters were deployed to the scene, as well as four ambulances, police and volunteer firefighters.
Two of the car's passengers, and the person trapped under the bus were helicoptered to Christchurch Hospital.
The bus had been travelling from Franz Josef to Christchurch.
• The Herald understands police from around New Zealand have been called upon to assist with translating victim and witness statements.
- additional reporting NZME, Newstalk ZB and Greymouth Star.