is the chaotic scene after a 7.8-magnitude earthquake sparked an avalanche on mount kumori , a 23,000-foot-high mountain just a few miles from everest , and gathered strength as it tore across the world 's highest peak .
half an hour after the initial quake , another magnitude-6.6 aftershock hit , followed by smaller aftershocks across the region .
eighteen people died in the avalanche , including four americans , and 61 were injured , according to nepal 's mountaineering department .