 Complete the following phrase:  On 25 April 2015, a devastating earthquake of moment magnitude of 7.8Mw killed nearly 9,000 people and injured nearly 22,000. It was the worst natural disaster to strike the country since the 1934 NepalBihar earthquake. The earthquake also triggered an avalanche on Mount Everest, killing 21. Centuries-old buildings including the UNESCO World Heritage Sites in the Kathmandu valley were destroyed. 