Three brothers who own Whakaari White Island are facing charges over the deadly eruption that occurred in 2019. 

The island was acquired by their grandfather in 1936 and has a history of eruptions and failed mining attempts. 

In 2019, the volcano erupted while tourists were visiting the crater and observing from a nearby cruise ship, resulting in the death of 22 people, including 17 Australians. 

The charges were brought by Worksafe NZ, alleging that the brothers and their company, Whakaari Management Limited, breached workplace safety laws.

The trial, which has been highly anticipated by the families of the victims, has finally commenced after more than two years of legal proceedings. 

Thirteen parties, including the Buttle brothers and their company, were initially charged, but some defendants have changed their pleas or had charges dismissed. 

The trial will examine the role of the supply chain in ensuring the safety of tourists, focusing on the defendants' alleged failure to obtain expert advice on conducting guided tours safely.

The trial is seen as a crucial step towards closure for the families affected by the tragedy. 

A separate coronial inquiry is ongoing to investigate the deaths. 

Meanwhile, guilty pleas have been entered by three helicopter tour operators who were charged with health and safety failings related to Whakaari. 

Worksafe NZ says it hopes that these actions will hold those responsible accountable and provide reassurance to the survivors and families of the victims. 

The trial is expected to shed light on the events leading up to the eruption and the circumstances that allowed tourists to be present on the active volcano.