Trapped in a half-star rated dome shelter high on Mt Ruapehu, William Pike felt certain he was going to die.
Huge boulders had smashed their way into the shelter, courtesy of a volcanic explosion, causing life-threatening injuries, before hypothermia set in and he drifted off into possibly his last sleep.
Miraculously he would survive, overcome huge challenges, and prove anything is possible if you set yourself goals and get out of your comfort zone.
Wanting to pass on the things he learnt to overcome adversity he set up the William Pike Challenge which about 100 schools throughout New Zealand are taking part in including Raumati South School where he visited on Wednesday.
The challenge is an exciting, year-long youth development and wellbeing programme where student must complete five outdoor activities, 20 hours of community service and 20 hours of passion projects.
In doing so, they're given opportunities to step outside of their comfort zone, develop and strengthen 21st century skills and experience extraordinary things.
Skills that are developed include resilience, confidence, connectedness, critical thinking and more - skills that William believes are essential for our youth to survive in tomorrow's world.
On September 25, 2007, William and his mate James Christie, who he had met at teacher's training college, decided to go on a mountaineering trip to Tongariro National Park.
William, then aged 22, was an experienced climber, having developed a passion for tramping and then mountaineering as a youth, but this would be James' first mountaineering trip.
After a long walk up a ski field, and up towards the Mt Ruapehu summit plateau, they came to a dome shelter which had snow surrounding it.
Their spirits were high, the views were extraordinary, and about 500m from the shelter was the crater lake.
Reaching the summit wasn't an option because of the snow conditions so they retreated to the shelter and bunkered down for the night.
At 8.20pm, while in their sleeping bags, a rumble was heard outside the shelter.
William sat up in the pitch black when suddenly the door popped off its hinges and blew in.
Looking outside he saw Mt Ruapehu erupting "spewing 1.5 million cubic metres of mud and rock up into the air".
"It was an unexpected eruption which no one could have predicted," he told the school.
"I was absolutely horrified."
Rocks "the size of basketballs and bigger" came crashing into the shelter as well as lots of water.
Debris pinned William, from the legs down, and he could "feel my bones in my right leg in particular breaking and crunching".
Then the mountain went quiet.
James, who wasn't injured, frantically tried to free his mate, but couldn't.
It was decided James needed to go down the mountain "to save his life and maybe my life as well".
James got his gear ready, stood outside to see a moonscape, then turned to William and said "where do I go?"
After William told him what to do, there was one more thing to say.
"I said 'James can you please tell my friends and my family that I love them'.
"I really didn't think I was going to see him or anyone else again. I was scared.
"He said 'nah tell them yourself' and then disappeared into darkness."
William did some mathematics and predicted he had "about five hours left to live" if he wasn't rescued.
"I thought pretty quickly that I would die in that building."
He thought about his family, things he wanted to do in life, and the fact there was nothing he could do except "not give up".
But hypothermia slowly took hold and he drifted off to sleep.
James scrambled down the mountain and after about an hour came across a snow groomer vehicle.
The alarm was raised and a rescue would soon be under way.
At about 1.30am an eight strong team arrived at the shelter, on a snow groomer, and entered to find William unresponsive.
He was dug out, put on the snow groomer, and taken down the mountain.
His body temperature was taken twice – it was 25C - normal body temperatures are about 36 to 37C.
A helicopter took William to Waikato Hospital where he was rushed into an operating theatre.
About 24 hours after the accident he woke up in the intensive care unit.
"I thought 'you beauty I'm alive'. I simply didn't expect to wake up."
Then he looked down at his legs and saw his right leg, from below the knee, had been amputated, it was a tough moment.
But as time went on he realised how lucky he was to be alive and set three goals – learn to walk, get back into the classroom, and get back to the dome shelter.
While he received great care at the hospital, words from a surgeon to the effect that William shouldn't expect to live the life he had beforehand, "really crushed me and I was upset for weeks".
William decided he had two options: take the easy track and listen to what the surgeon said, or take the hard track and chase his love of adventure.
The hard track won out.
It wouldn't be easy but two things would help him including having a sense of purpose as well as supportive family and friends.
He managed to walk again, with the use of a prosthetic leg, got back into the classroom but getting back to the dome shelter proved difficult and there were a number of failed attempts.
"Part of me thought I would never get up there again and I put it into the too hard basket."
But he kept finetuning his prosthetic leg as well as getting fitter and stronger.
Five years after the accident William and James returned to the mountain for another attempt.
"After about six hours of climbing, I couldn't believe it, we came through the mist and there was the dome shelter.
"It was an absolutely incredible and a momentous occasion."
Years later after summiting Antarctica's Mt Scott, as part of group climb, the "penny dropped" as William made his way down.
Everything he had been doing was about "stepping outside my comfort zone".
"That is the key to my success.
"I believe when we continue to step outside our comfort zone it becomes a whole lot easier and we become more resilient, we see opportunities instead of obstacles, we become more closer to achieving our absolute best.
"Nothing great was ever achieved by sitting or standing inside your comfort zone."