An earthquake with a magnitude of 6.9 struck the India-Nepal border, killing 38 people in India and 7 in Nepal and injuring over 90 in India. Earthquakes occur due to a sudden crack in the earth's crust caused by a buildup of stress over time, and can be triggered by volcanic eruptions or activity at fault margins. The earthquake started in northeastern India and Nepal on Sunday night, and the death toll continued to rise above 38 people from the affected regions.