An 'emotional” documentary about the aftermath of the Whakaari/White Island eruption is set to air on TV Three tonight – almost a year on from the fatal explosion that killed 21 people.

Stories of Survival sheds light on the experiences of eruption victims, their family and other's involved in the Whakatane tragedy.

There were 47 people – made up of international tourists from the cruise ship Ovation Of The Seas plus local guides – on the volcanic island off the coast from Whakatane when the eruption happened just after 2pm, on December 9 last year.

Filmmaker Irene Chapple of The Eruption: Stories Of Survival says the documentary is 'pretty emotional”.

Irene, an experienced journalist, producer and filmmaker, was working as a freelancer on The Project on the day of the eruption.

She was immediately drawn to the story and moved quickly to secure NZ On Air funding to investigate the effects the disaster had, particularly on the local Whakatane community.

'From the moment I heard about this story, I was absolutely astounded and impressed by the heroism of the local people,” she told Stuff.

'I found it fascinating what people had done in this time of crisis, how they had responded.

'This is part of New Zealand history so, to me, it was a really important story to tell – what happened that day and what happened next to those people involved.

'Whakatane's a small town and they all know each other and they all came together to help in this tragedy.

'The more I went into the story, the more people I spoke to, the more I saw the strength of spirit from a small New Zealand town.”

Irene talked extensively with teenage survivor Jake Milbank who was one of the guides on the island that day.

The family of fellow guide, 40-year-old Hayden Marshall-Inman – one of the two people still missing – also contributed to the documentary.

'So they are really what this film is all about,” Irene says.

'However, there is also a beat-by-beat what happened on the day and in the immediate aftermath, at Whakatane Hospital, at Middlemore Hospital.

'We then go through the recovery of the bodies that remained on the island and we speak to the Special Operations soldier who led that team.”

She says what the documentary does not try to do is apportion blame.

'This film was never going to be an exploration into the investigation and, if it had been, I don't think we'd have ultimately been talking to the same people because they wouldn't have wanted to participate because it's so sensitive,” Irene says.

'Everyone is extremely aware of the workplace investigation, which is very active at the moment.”

She hopes viewers will react the same way she did to hearing the stories of both the survivors and those of the victims' families.

The Eruption: Stories Of Survival airs tonight on Three at 8.30pm.

-Stuff