Indonesian island of Sumatra triggered a tsunami that killed around 230,000 people across a dozen countries, reaching as far as East Africa. But Indonesia's Aceh province, located closest to the earthquake's epicenter and with 18 of 23 districts and cities located in the coastal line in the Northern side of Sumatra,

On Dec. 26, 2004, a 9.1 magnitude earthquake struck off the west coast of Sumatra, causing a massive wave that devastated Asian coastal communities across thousands of miles.

Banlue Choosin has been monitoring the seas around Thailand's southern Phang Nga province for signs of abnormality for nearly two decades. The 59-year-old is a former fisherman, and his experience and knowledge of the sea are why his coastal community in Ban Nam Khem village relies on him to monitor nearby waters after earthquakes.

Survivors and victims' relatives will next week mark the 20th anniversary of the 2004 Indian Ocean earthquake and tsunami, which killed more than 220,000 people across more than a dozen countries.