The magnitude 9.0 earthquake that struck the area off the western coast of northern Sumatra on Sunday morning, 26 December 2004, at 7:59 am local time (00:59 GMT) triggered massive tsunamis that inundated coastal areas in countries all around the Indian Ocean rim, including India, Indonesia, Sri Lanka and Thailand. The region is historically prone to seismic upheaval due to its location on the margins of tectonic plates. However, tsunami waves of this magnitude are rare and the level of preparedness was very low.
