"I can see why people are drawn to it, I was always struck by the fact that volcanoes can be somewhat unpredictable, even with the best monitoring."
When Whakaari erupted on December 9 last year, Klemetti was at the American Geophysical Union meeting in San Francisco.
"When I did see the headline come across on Twitter ... I had this feeling of like, this is exactly the sort of thing that I hoped wouldn't happen, that ended up happening."
When Klemetti was offered the opportunity to go to the island, back in 2009, he said no.
"My level of risk management there, the amount of nervousness I had about doing a trip like that was high enough that I thought, it's not worth probably doing, although people who I know who are volcanologists who have done it, say it's remarkable and I'm sure it would have been.
"But I just could not bring myself to do it."
University of Auckland volcanologist Shane Cronin suspects people began to woefully underestimate the risk posed by Whakaari.
"Primarily because the numbers of people visiting the island, that's increased hugely," Cronin said.
Once tours were few and far between - and even stopped during winter.
"These days what was going on: there were people coming off cruise ships, so there were multiple trips per day, people were coming in with helicopters, with boat tours.
"The sheer number of people coming to the island - not only just at once, but continuously - meant that our exposure to the risk was much, much higher."
Three years before last December's eruption, there was an eruption of a similar size at Whakaari - except it happened at night.
"We had a series of these near-misses and we were pretty well aware of that at a national level, that a lot of our tourist volcanoes have this sort of sudden onset risk, and it was ranked as one of the highest likelihood events, in terms of a mass casualty event," Cronin said.
Klemetti said he would be hesitant to open the volcano up to the same level of tourism again.
"Maybe you could have tours that tour around the island, to see it from a boat, but that again, you'd need to know what the level of hazard and level of activity the island might be showing at the time.
"But having people with boots on the ground on the island on a regular basis just feels like it's just asking for something like this to happen again."
Cronin was not convinced either.
"I think it's a great place to visit when things are in a calm level, I'm just not sure we are in a position to be able to provide such a clear sense of security about that."
When it was announced last week charges were being laid over the disaster, WorkSafe chief executive Phil Parkes would not say whether tourists should be allowed to return to Whakaari because that was outside the scope of the investigation.
"Our investigation was focused on the obligations of the individuals and companies who were taking people to the island, whether they met their health and safety obligations, any discussions around the future of the island were outside the scope of the investigation," he had said.
The Ministry of Business, Innovation and Employment is reviewing the adventure activities regulations - looking specifically at activities that revolve around natural hazards.
The Department of Internal Affairs is also working with other government agencies about future access to Whakaari/White Island.
