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

988K views · 20K reactions | Michael Phelps won his first Olympic gold medal 16 years ago at Athens 2004. Enjoy the very first of 28 Olympic medal races. USA Swimming Team USA | Olympics | Facebook