An earthquake occurs when tectonic plates beneath the earth's surface separate suddenly, causing the ground to tremble. This happens because the earth has an inner core and is made up of many tectonic plates that can shift past each other. When the plates separate rapidly, it makes the earth shake and results in an earthquake, which can cause buildings to collapse, fires, cracked roads, and people to yell in panic as their bodies shake uncontrollably and they become frightened by the sounds of destruction.