The 2004 Indian Ocean earthquake was an undersea mega thrust earthquake that occurred on Sunday, December 26, 2004, with an epicenter off the west coast of Sumatra, Indonesia. The earthquake was caused by subduction and triggered a series of devastating tsunamis along the coasts of most landmasses bordering the Indian Ocean, killing over 230,000 people in fourteen countries, and inundating coastal communities with waves up to 30 meters (100 feet) high. It was one of the deadliest natural disasters in recorded history.