It has been 18 years since the deadly Indian Ocean tsunami killed 230,000 people on December 26, 2004. The tsunami set off by a magnitude 9.1 earthquake hit a dozen countries, from Indonesia, to India and Africa’s east coast. | TRT World

In 2004, a large earthquake in the Indian Ocean triggered the largest tsunami in recorded history. One of the countries hit by the tsunami was Sri Lanka, where the wave caused one of the worst train disasters in human history when it hit the Queen of the Sea passenger line, which was carrying 1,500 passengers along Sri Lanka's west coast. Watch Destruction Decoded on Wednesdays at 8pm on National Geographic UK. | National Geographic UK