Follow link to this Geological Society video shows the plate tectonic explanation for the common incidence of earthquakes in this zone.
The CCTV footage above shows the effect of a magnitude 7.8 earthquake on a swimming pool in Nepal.
The earthquake led to a prompt declaration of a national emergency, as after shocks continued to bring down already weakened buildings. But the response to the earthquake by the Nepalese government has been very poor: they could not cope with the disaster. See the news report of this. A BBC report also deals with the poor government response:
Avalanche on Everest triggered by the earthquake.