Tourists received no health and safety warnings before they landed on New Zealand’s most active volcano ahead of a 2019 eruption that killed 22 people, a prosecutor says.

There were 47 people on White Island, the tip of an undersea volcano also known by its Indigenous Maori name Whakaari, when superheated gases erupted on December 9. 

Most of the 25 people who survived were severely burned.

The island’s owners, brothers Andrew, James and Peter Buttle; their company Whakaari Management; and tour operators I.D. Tours NZ and Tauranga Tourism Services went on trial on Tuesday in Auckland District Court for allegedly failing to adequately protect tourists and staff.

Prosecutor Kristy McDonald said in opening the prosecution case the eruption at the popular tourist destination was not predictable but was foreseeable. 

The 20 tourists and two tour guides who died – 14 Australians, five Americans, two New Zealanders and a German – were given no warning of the risks, she said.

“They were not given the opportunity to make any informed decision about whether they wanted to take the risk of walking into the crater of an active and unpredictable volcano that had erupted as recently as 2016,” Ms McDonald said.

“The business of tourism on Whakaari was a risky business. 

“It involved tours to an active volcano, taking people to the heart of the crater in circumstances where no one could predict when an eruption might occur, and if an eruption did occur, those on Whakaari were likely to die or suffer very serious injury. 

“And tragically, that risk was realised.”

Ms McDonald said the company that owned the volcano – Whakaari Management, which she called WML – failed to understand the risk, failed to consult with tour operators on the hazards, failed to ensure appropriate personal protective equipment was provided to tourists and staff, and failed to provide an adequate means of evacuation.

The company left tour operators to monitor the changing risk. 

An eruption on April 27, 2016, occurred at night without warning when no one was on the island. 

That should have prompted the owner to review the risk assessment, Ms McDonald said.

The volcano had gone through 42 “eruptive periods” since colonial records began in 1826, she said.

After the 2016 eruption, NZ geology agency GNS Science banned staff from visiting the crater floor until further notice because of the “heightened state of volcanic unrest”, Ms McDonald said.

Despite knowing this, several operators continued taking tourists to the crater from the day after the eruption, she said.

WHL, which made a profit of $NZ1 million ($A930,000) a year from tourists, could have paid GNS for a formal risk assessment but did not, she said.

She blamed the Buttle brothers for the WML’s failure to assess the volcano danger.

“The Buttles knew they could obtain expert advice from GNS for a fee,” Ms McDonald said.

“They chose not to.”

I.D. Tours NZ and Tauranga Services failed to ensure 38 passengers, who had travelled from Australia aboard the Royal Caribbean cruise ship Ovation of the Seas and were on the volcano when it erupted, had been properly warned of the risk, Ms McDonald said.

Those 38 people “did not receive any health and safety information about volcanic activity or volcanic risk prior to the tour”, she said.

Ms McDonald said the only way off the island other than by aircraft was a 90-year-old jetty that was too small for tourist boats to dock at. 

Survivors had to climb down a ladder to inflatable boats.

“A number of victims were badly burnt and this transfer was very painful,” Ms McDonald said. 

“Some of them were losing the skin off their hands as they attempted to climb down the ladder. 

“Some were unable to use the ladder and were pushed or fell into the inflatable boats.”

Three helicopter tour operators pleaded guilty last week to safety breaches.

Each of the companies faces a maximum fine of NZ$1.5 million ($1.4 million). 

Each of the brothers charged faces a maximum fine of NZ$300,000 ($277,000).

The trial being heard by Judge Evangelos Thomas without a jury and will resume on Wednesday.

It is scheduled to run for 16 weeks.

–AAP