The bus that crashed returning from Tūroa ski field on Saturday - killing a young girl - previously failed its Certificate of Fitness nine times.
The Ruapehu Alpine Lifts (RAL) bus rolled and crashed on Ōhakune Mountain Road just five minutes into the 17km journey. It was carrying 31 passengers.
Three people were seriously injured - a man and two women - and were airlifted from the site and remain in a stable condition at Waikato Hospital.
The Mitsubishi Fuso bus was imported from Japan in 2004 and failed its Certificate of Fitness nine times over the 14 years.
Different to a warrant of fitness - the certificate is a regular check for heavy vehicles to ensure they meet required safety standards. The inspection covers many aspects, including brake condition and operation.
The 24-year-old bus passed its most recent inspection at the end of May.
RAL Lifts chief executive Ross Copland said in a statement: "Our thoughts are with the passengers and families involved in the crash, as well as our driver.
"The crash is under investigation by the police and we will not be making any further comment at this stage."
Steven Hatch, an automotive diesel mechanic, has been working with buses and trucks since 1977.
He said it was not uncommon for a vehicle to fail its inspection as inspectors were "very pedantic".
Mr Hatch said he worked with many Mitsubishi Fusos in his time and most were fitted with hydraulic brakes.
As such, it would be very unusual if the accident was caused by loss of brakes, he said.
Passengers on board the bus described the moment things went wrong.
They said there was a loud honking noise and the sound of air whooshing whenever the driver put his foot on the brakes.
Steven Hatch offered a possible explanation.
"It could be low on brake fluid. It could be low on the air part because even though they are a hydraulic brake system they are air assisted."
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Back to business at Tūroa
It was back to business as usual at the Tūroa ski field today.
Johl Dwyer and his daughter caught a replacement shuttle but boarded the vehicles with some reservations.
"Just everyone was quiet. Nothing out of the ordinary, just everyone was pretty quiet."
Ken Summerhaus, who drives a bus to and from the Tūroa ski field for a private company, said the crash was on his mind today.
"Yeah, I'm comfortable driving the big buses on the mountain because we've got a good safety record but you still think about it yeah, it could have happened to anybody."
It is believed the girl who died was 11 years old. The police said due to the nature of her injuries, they were yet to formally identify her.
A view from the inside
Photos taken inside a bus, understood to be operated by RAL, show seats tied up with wire and a handle which has fallen off the back of a passenger seat.
State of what is believed to be a Ruapehu Alpine Lifts' bus. Photo: Supplied.
Sophie Leather was a passenger on a different bus travelling between National Park and Whakapapa on Saturday.
She purchased tickets from the kiosk at National Park Village, which only sells tickets for RAL's shuttle service.
She was so concerned about the state of it, she took photos.
"The chair in front of me was fully broken, not held up by wires and I was trying to hold that up with my feet.
"A lady went to go brace herself and her child and just going around a small corner the entire handle came off the chair and so we were pretty horrified at that to be honest and all started talking about how dangerous it was."
The visible safety issues made her question whether other buses operating in the same area were in a similar condition.
"A lot of people are just initially trying to put the blame on the bus driver, but I feel that even if it was the bus driver's fault the conditions of the safety in the bus could have changed the outcome drastically."
RAL chief executive Ross Copland and chairperson Murray Gribben both refused an interview on Checkpoint.