(CNN)With Indonesia, the question is not whether an earthquake will occur but when.
The Southeast Asian archipelago nation is reeling after yet another powerful earthquake struck Friday, followed by a tsunami, leaving nearly 400 people dead and hundreds injured. The walls of water engulfed towns, swept away buildings and tossed cars like toys.
Indonesia is prone to earthquakes because it’s on the Ring of Fire, an arc of volcanoes and fault lines in the basin of the Pacific Ocean. The area shaped like a shoe spans 40,000 kilometers (25,000 miles) and is where a majority of the world’s earthquakes occur.
