An earthquake happens in Sumatra in Indonesia. That tectonic movement triggered a tsunami, which then crashed into the shorelines of seven countries in the Indian Ocean, causing havoc.

Hellmut Issels
Debris, wreckage, devastation and human suffering is everywhere on coastline after coastline of India, Indonesia, Sri Lanka and Thailand.
The death toll has topped 50,000 and is rising.
Update:1 Jan
3 days latter and the death toll has tripled to 150,000 and still rising. The vast majority of the deaths are in Indonesia and Aceh which are the least assessed areas because of logistical constraints.