Late last night, Sequoia Di Angelo, daughter and sister of the climbers, emailed the Herald: "It is with great sorrow that I confirm the tragic deaths of my beloved brother and father, Denali and Marty Schmidt. May their spirits rest in peace and their smiles never be forgotten."
British climber Adrian Hayes - one of those who turned back - said the Schmidts were well known, highly experienced and very strong mountaineers - the last people many would expect to be killed on a mountain.
"Sadly, at times the mountains do not differentiate between ability and experience, least of all K2. The poignancy of the tragedy is not lost in that, had the rest of us not turned back that day ... we also all would have been sleeping at Camp 3 when the avalanche struck," Mr Hayes posted on Facebook from base camp last night.
New Zealand Alpine Club general manager Sam Newton said Mr Hayes' report confirmed their worst fears. He called Marty Schmidt one of New Zealand's greatest mountaineers.
Before setting off on the climb, Marty Schmidt spoke of his respect for K2 and of how much he enjoyed climbing with Denali. "It's so much fun. We have a great time for three months. Not many fathers get that kind of time with their grown-up sons," he said in an interview with Skins, one of his sponsors.
In a blog, he wrote: "Cutting away from the horizontal world to the vertical world has so much power and grace attached to it that I love to journey this way many times of the year. I have been doing this now for over 38 years ... Can't see myself stopping anytime soon either."
Mr Schmidt, born in California, had been living in the Far North with his wife, Giannina Cantale, son and Sequoia, 22. He divided his time between NZ, the US and Canada.
A professional guide, he climbed some of the world's tallest mountains without oxygen, including five of more than 8000m. He climbed and guided many times on the Seven Summits - the tallest mountain on each of the seven continents - and got to the top of Mt Everest twice.
Despite K2's dangers, he said in a recent interview that it was the one he loved the most. "I've climbed a lot of the world's biggest mountains but K2 is the one I respect the most. I've been on it twice without summiting. I'm just called to it all the time."
Mrs Rippel last heard from the pair on Monday last week when they left a message saying they were planning on a summit push at the weekend and asked for a weather report.
"The winds were showing good speed for a push but it was apparent there had been a lot of precipitation that had me concerned," she said.
A search for the Schmidts was set to start yesterday morning.
They had been aiming to reach the peak either on Sunday or yesterday, local time. If that bid had been successful, Marty Schmidt was planning to make another from the more difficult northern Chinese side next year, which he was going to film.
"I want to show the world what it's like. It's like going to the moon without a Nasa rocket," he wrote.
Mr Schmidt is also the mountain ambassador for Macpac and on July 22, he wrote a blog post from K2's base camp on the NZ company's website.
"Bad weather has set in for the next few days, resting and training and prepping gear for our K2 summit push ... Denali and I hope everything clicks so that we can be the first dad and son team to reach K2's summit and [the] ... first alive Kiwis to do so. Great thoughts to you all in NZ and the world."
K2
* Kills one climber for every four who summit
* Conquering the "holy grail of mountaineering" means dealing with steeper, icier slopes and less predictable weather than on Mt Everest.
* 280 people have summited it since 1954, when it was first conquered.
* Considered to be the world's deadliest mountain.
Source: Mental Floss magazine
