A strong earthquake occurred off the island of Sumatra on the morning of December 26, 2004, sending tsunami waves over a wide area ranging from Southeast Asia to eastern Africa.
More than 220,000 people were killed or went missing. Aceh was among the hardest hit by the tsunami, with the death toll at 160,000 people.
Indonesia experiences frequent seismic and volcanic activity due to it position on the Pacific "Ring of Fire" where tectonic plates collide.
In 2018, a tsunami triggered by a volcanic earthquake killed nearly 500 people in Banten province.
