Robbie Phillips, 25, from Burdiehouse, Edinburgh, and Willis Morris, 20, from Glasgow, conquered the challenging route on the north face of the Eiger in Switzerland.
A first attempt three weeks ago had come to an end when a thunderstorm brought down rocks around them and the Japanese team were rescued by helicopter.
It was only when they returned from a second, successful attempt on Saturday that they learned two colleagues had perished in the rockfall.
Mr Phillips, speaking from Switzerland to The Scotsman, said: “We were close to doing it on our first attempt, which is amazing. Then when we were on the wall, we got hit by a freak thunderstorm and it was very dangerous and lots of rocks fell - huge boulders the size of cars - and we had to escape off the wall, pretty much for our lives.
“On a wall like this, you get to a point where you either turn back or you keep going. And the thing you’re weighing up is keep going and make the ascent, but potentially also risk your life.
“Because if something changes in the weather dramatically, or something serious happens and you can’t get off the wall or it will take too long to get off the wall before something serious happens, then it could just be the end of you.
“I think sometimes when you get caught up in the moment of attempting something like this, you do forget how serious an attempt it can be.”
Mr Phillips said even after a tragedy such as that, he knew it was down to freak bad weather, the forecast was much better and they could take more risk going higher. The Scottish pair became the fourth team to conquer the Paciencia, or Patience, route on the Eiger and followed fellow Scot Dave MacLeod, who Mr Phillips credits as a major influence on his career.
Initially Mr Morris had to return to Glasgow earlier in August until an anonymous donation allowed him to return to Switzerland. They set out on Tuesday and carried out the climb on Thursday and Friday, then abseiled in 60m stretches down 900m.
The steep and exposed route up a nearly flat wall of 700m then changes to a final section which is more dangerous because of falling ice and rock. Former George Watson’s pupil Mr Phillips said: “It’s probably the best feeling you can possibly have. Climbing is a very personal thing. It’s not necessarily always about getting to the top. It’s more about the challenge of overcoming the obstacles.
“It’s technically hard, but it’s also consistently hard - that’s why this route is regarded as the hardest Alpine route in Europe. It’s cool to be doing a piece of history.”
Mr Phillips is now setting his sights on a free climbing event, skydiving in Spain in November, climbing winter routes in Scotland, and free climbing the famed El Capitán in Yosemite National Park in California.