Questions are being raised over why people were able to visit an active volcano, why authorities can't get there right now, and what will happen as a result.
Whakaari / White Island, off the coast of Whakatane, started stirring on November 18. The volcanic alert level was raised from 1 to 2, meaning moderate to heightened volcanic unrest and potential for eruption hazards.
The volcano erupted suddenly on Monday afternoon, leaving multiple people dead and lots of questions to be answered. Volcanologist Raymond Cas says Whakaari was a disaster waiting to happen.
"So many hazards conspire together in this tight-closed, confined space in the crater of this volcano that makes it likely that whenever an eruption occurs, someone is going to get badly hurt or killed," he told Newshub.
"This is not a volcano that can be trusted."
As well as a criminal investigation, Worksafe has launched an investigation into the tourism operations on the island and the risks associated with that work.
While the focus for police and emergency services is on recovering the bodies, the families of those killed are asking why - and the world is watching.
A CBS News bulletin said there are "questions tonight about why people are allowed to set foot on one of New Zealand's most active volcanoes just weeks after geologists warned of volcanic unrest".
Prime Minister Jacinda Ardern acknowledges there will be people wanting to know what went wrong, saying: "There are questions rightly being asked that do need to be answered."
Newshub asked Tourism Minister Kelvin Davis why people were allowed on the island. He said tourism to White Island has been happening for 30 years.
"Now isn't the time to be asking those questions when we still have bodies on the island," he said.
It's not just the question of why people were allowed on the island - families are asking why emergency services can't get there now.
"[That's] certainly that's a focus of police," the Prime Minister said. "As you can imagine they're very keen to get back there, they're ready to go."
The air on Whakaari is now toxic and there's a 50 percent chance of another eruption within 24 hours.
Police Minister Stuart Nash says he's confident police have done enough to get to the island to recover the missing.
Family of one of the victims said it feels like the 2010 Pike River controversy all over again when a rescue team didn't enter the mine because of the safety risks.
Nash described the comparison as "very unfair".
National leader Simon Bridges said that sort of "grief, frustration and anger from family members is understandable".
The Government is promising to investigate the families' concerns.
"Those aspects will not be covered over [and will] not be hidden - we'll get to the bottom of it at a time we properly can," Deputy Prime Minister and New Zealand First leader Winston Peters said.
Right now, the priority for everyone is the victims and their families.
"We say to those who are lost and grieved you are forever linked to our nation and we will hold you close," the Prime Minister said in a speech to Parliament on behalf of the Government.
The Opposition's deputy leader Paula Bennett also stood in Parliament to honour the victims, saying: "Our land has taken them our land now looks after them."
The Prime Minister says nothing is being ruled out in relation to investigating the tragedy, including a Royal Commission of Inquiry.
Deputy Police Commissioner John Tims confirmed at a Tuesday afternoon press conference that the terms of reference for the police investigation would be developed over the next few days.
"Police are working really hard at the moment to provide support to all the families of loved ones who were killed or injured in the eruption," he told reporters at Police HQ in Wellington.
There have been five fatalities from the eruption. Their bodies have been transported to Auckland where a post-mortem will be carried out, Tims said.
There are approximately eight people missing and presumed dead.
