The presence of numerous unstable blocks of ice (called seracs) in and above the Khumbu Icefall encourages climbers to try to pass through as quickly as possible, usually in the very early morning before temperatures rise and loosen the ice. In the spring of 2012 Russell Brice, of the guiding company Himex, called off guided ascents run by his company due to safety concerns. He was worried about the stability of a wide ice cliff, or ice bulge, on Mount Everest's western shoulder that could endanger the route through the Khumbu Icefall, if it collapsed. When I see around 50 people moving underneath the cliff at one time, he commented, it scares me. However, Brice and Himex returned to the south side of Everest for the 2014 climbing season. Mountaineer Alan Arnette reported that this ice bulge had been a known hazard for years and had discharged ice into the Khumbu Icefall almost every season. He added that, In 2012 it narrowly missed many climbers. According to writer and mountaineer Jon Krakauer, the 2014 ice avalanche was triggered when a block of ice the size of a Beverly Hills mansion broke off from the bulge.