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

After a massive earthquake triggered the deadliest tsunami in recorded history, multiple waves hit Thailand. As the waves reach the beaches of popular resorts, locals and tourists work together to save lives. Survivors separated by the waves desperately search for their loved ones. Discover the power of the human spirit through stories of hope, hardship, and heroism from the 2004 Indian Ocean tsunami. Tsunami: Race Against Time premieres Monday November 25th at 9pm on National Geographic UK. | N

The tsunami that struck Thailand on December 26, 2004, was caused by a massive earthquake with a magnitude of 9.1 to 9.3 on the Richter scale. The epicenter of the earthquake was located off the west coast of northern Sumatra, Indonesia. The earthquake was caused by the Indian and Australian tectonic plates moving against each other, resulting in a large-scale displacement of water. This displacement created a series of massive waves that traveled at high speeds across the Indian Ocean, eventual