A tsunami originating from a far away source, generally more than 1,000 km away. Less frequent, but more hazardous than regional tsunamis, are ocean-wide or distant tsunamis. Usually starting as a local tsunami that causes extensive destruction near the source, these waves continue to travel across an entire ocean basin with sufficient energy to cause additional casualties and destruction on shores more than a 1,000 km from the source. In the last 200 years, there have been at least 21 destructive ocean-wide tsunamis. The worst tsunami catastrophe in history occurred in the Indian Ocean on the 26th December, 2004, when a magnitude 9.1 earthquake off of the northwest coast of Sumatra, Indonesia produced a ocean-wide tsunami that also hit Thailand and Malaysia to the east, and Sri Lanka, India, the Maldives, and Africa to the west as it traversed across the Indian Ocean. Over 225,000 people lost their lives, and more than 1 million people were displaced, losing their homes, property, and their livelihoods. The magnitude of death and destructiveness caused immediate response by the world's leaders and led to the development of the Indian Ocean tsunami warning and mitigation system in 2005.