Nearly 15 years ago Arif Munandar woke up in a body bag.
That was four days after a tsunami swept through his village in Indonesia's northern Aceh province.
Though Munandar had miraculously survived he also lost 24 family members, including his wife and three children.
Today it's his mission to keep his village's tsunami early warning system well maintained., through his job as a radio communication technician.
(SOUNDBITE) (Bahasa Indonesia) TSUNAMI SURVIVOR AND RADIO TECHNICIAN AT ACEH DISASTER MITIGATION AGENCY, ARIF MUNANDAR, SAYING:
"We will continue to do what we can, providing information to the community in order to minimize the number of casualties when such a disaster happens again. We don't want a large number of casualties, so, we need to anticipate disasters - even if that means we need to do it manually - we must provide every support we can."
On December 26 2004, a 9.1 magnitude earthquake opened a faultline deep beneath the Indian Ocean, triggering a tsunami as high as 17.4 meters.
More than 230,000 people died in 13 countries including Indonesia, Sri Lanka, India and Thailand.
Aceh bore the brunt of the disaster. According to government and aid agency figures, 128,858 people died there and more than 37,000 are still listed as missing.
Over $400 million has since been spent on an early warning system across 28 countries but challenges remain, including maintenance difficulties and a lack of equipment such as tsunami buoys.
Speaking via Skype from India's Hyderabad, Srinivasa Tummala - who heads the Indian Ocean Tsunami Warning and Mitigation System - said there are gaps in the system.
(SOUNDBITE) (English) HEAD OF INTERGOVERNMENTAL COORDINATION GROUP FOR THE INDIAN OCEAN TSUNAMI WARNING AND MITIGATION SYSTEM SECRETARIAT, SRINIVASA TUMMALA SAYING:
"So you need more stations, and then more importantly you need more data sharing, real time data sharing among member states and with this tsunami service providers so that the accuracies and the timeliness of tsunami warning can be improved."
One focus is community preparedness including carrying out regular drills a nd in the coastal Ban Nam Khem village, in southern Thailand, which lost more than half its population, the national anthem is played weekly on the tsunami warning tower.
A test run for a nightmare they hope will never recur.