Earthquakes have been wreaking havoc in Haiti since at least the 18th century, when the city of Port-au-Prince was destroyed twice in 19 years.
Saturday’s powerful quake killed hundreds and injured thousands more.
Eleven years earlier a temblor killed tens of thousands of people, if not hundreds of thousands.
Haiti sits near the intersection of two tectonic plates that make up the Earth's crust.
Earthquakes can occur when those plates move against each other and create friction.
Haiti is also densely populated.
Plus, many of its buildings are designed to withstand hurricanes — not earthquakes.
Those buildings can survive strong winds but are vulnerable to collapse when the ground shakes.