Getting 20 children to safety was John Petrie's first thought as Mt Tongariro erupted barely two kilometres away.
Grey smoke billowed out of Te Maari crater on Wednesday as the Gulf Harbour School 12-year-olds and 10 adults were descending nearly six hours into a nine-hour and 19.4km Tongariro Crossing trek.
The children arrived back in Gulf Harbour unharmed and on schedule on Friday evening after a week's camp at Tongariro National Park.
"We were walking out of the valley, just about two kilometres away from Ketetahi Hut, when we saw grey smoke billowing out of the crater," principal John Petrie says.
"There was no noise, no smell, no explosions - nothing. "It was quite stunning to see the smoke developing slowly."
The children had mixed emotions, he says.
"They went wow, and some whipped out their cameras to take photos, while some were quite scared and some were almost oblivious to what was happening."
"But when the smoke continued to rise, and as it grew bigger and bigger we went ‘this is big, let's go'," he says.
The group met a guide leading a group of visitors, and together they went down a ridge away from the scene.
"When we reached Ketetahi Hut, there were two other tracks there. One had been closed down so we took the older track, and that led us further away from the mountain."
Parents were kept updated through Facebook, the school's text messaging system and its website. "There was no panic," Mr Petrie says. "Everyone worked together, and we were very relieved to get off the mountain."
"We're really proud of our kids with their response and maturity, and the way we all managed a challenging situation."
The trip marks Mr Petrie's 21st year taking year 8 students on their Tongariro camp but it is not every day you see a volcano erupting, he says.
"And we're definitely going back again next year."
- © Fairfax NZ News