The second highest mountain in the world – just 237 meters shorter than Mt. Everest – has a reputation for being far more hazardous than Everest, and the statistics don’t lie.

Historically, for every 100 climbers who have made it to the summit of Everest, four have died. For every 100 climbers who have summited K2, 29 have died. A scant 306 people have ever stood on the summit of K2, compared to more than 5,600 Everest summiters.

The path to basecamp crosses glacial rivers. © Ahmad Abdul-Karim Photography

The weather is worse on K2. The climbing is more difficult, with two technical sections, House’s Chimney and the Black Pyramid. Once safely past those, climbers must navigate the narrow Bottleneck couloir, forcing themselves underneath a set of massive seracs.

Porters at a K2 camp. © Ed Darack

In 2008, part of the serac collapsed, cutting fixed ropes and avalanching onto the route, which made navigating the Bottleneck more technical for the parties who had climbed above it. In the single worst day in K2’s history, 11 climbers died. A new documentary film, The Summit (trailer below), premiered at the Sundance Film Festival in January 2013, and attempts to explain the obsession with K2, the dangers of climbing it, and the 2008 tragedy.

Although it has a reputation to be 'the Savage Mountain', K2 is not statistically the deadliest 8,000-meter peak—Annapurna, the first of the 8000ers to be climbed, is. For every 100 climbers who summited Annapurna, 34 have died. K2, however, draws far more interest, maybe because of its reputation.

The Gilkey Memorial at K2 base camp. © Credit: Nadeem Khawar

The major disasters, in 2008, and in 1986, when 13 climbers died over the span of several weeks, have put K2 in the news, and although expeditions return every year, the mountain and its weather are fickle. In 2009 and 2010, no one summited K2. In 2012, more than 30 climbers summited, 28 of those in a single day of great weather on July 31. This year’s teams no doubt hope for similar success.

According to Raheel Adnan's Altitude Pakistan blog and the Japanese team's blog, 21 climbers from various expeditions planned to leave K2 Base Camp on July 24, hoping to take advantage of an expected good weather window beginning on July 27.

Climbers left at 6am local time. Four teams – a Japanese team, an Argentinian team, and two international teams with members from New Zealand, Australia, Nepal, Greece, the UK, and Canada—are on the mountain. All climbers will be on the standard Abruzzi Spur route.

Spanish climber Alex Txikon, who planned to climb the Cesen route without oxygen with Mexican Benjamin Salazar and Spaniard Felix Criado, has apparently turned back at Camp 2 because of too much snow high on the route.

A Swiss team (Mike Horn, Fred Roux, and Kobi Reichen) also planned to climb the Cesen Route, but Mike Horn posted on his blog on July 20 that he and Fred Roux left for Broad Peak to attempt to rescue the three Iranian climbers who were lost around 8,000 meters and died.