 Complete the following phrase:  In the 2014 and 2015 seasons, tragedies killed more than a dozen people. There were few summits from the south in 2014 and none in 2015. On April 18, 2014, 16 Sherpas were killed in an avalanche in the Khumbu Ice Fall. On April 25, 2015, 19 people were killed in an avalanche at base camp following a 