 The couloir is located only 400m below the summit, and climbers have to traverse about 100m exposed to the seracs to pass it.Due to the height (8200m) and the steepness (50-60 degrees) this stretch is the most dangerous part of the route.According to AdventureStats, 13 out of the last 14 fatalities on K2 have occurred at or near the Bottleneck.