JAKARTA: Arif Munandar was pronounced dead but he woke up in a body bag four days after the Indian Ocean tsunami swept away his village in Indonesia's northern Aceh province 15 years ago.
When the magnitude 9.1 quake opened a fault line deep beneath the Indian Ocean, it triggered a wave as high as 17.4 meters, killing more than 230,000 people in Indonesia, Sri Lanka, India, Thailand and nine other countries.
Munandar's home in Aceh province bore the brunt of the disaster, where a total of almost 130,000 people were killed, according to statistics compiled by the government and aid agencies.
Twenty-four of Munandar's family members, including his wife and three children, died in the tragedy.
But Munandar and tens of thousands of others were allowed to return to the same low-lying areas of Banda Aceh despite the continuing risks of tsunami and other coastal hazards like flooding and liquefaction, Reuters found.
Officials and experts said poor enforcement of building codes, a lack of government resources for relocation, and an entrenched reluctance to leave, mean that many survivors are still living in the area.
Munandar, who has since remarried and has two young children, worries about protecting his new family from potential disaster. He works as a radio technician in the local disaster mitigation agency and makes weekly checks on the warning system in his village.
"We need to anticipate disaster even though that means we need to do it manually, we must provide every support we can," Munandar says.
Tsunami evacuation buildings, early warning systems and sea-level buoys are scattered across the coastal areas of Aceh province, but upkeeping of facilities like evacuation centres and new equipment are still lacking, head of the agency in the region, Sunawardi said.
More than US$400 million has been spent across 28 countries on the early-warning system, comprising 101 sea-level gauges, 148 seismometers and nine buoys.
In Sri Lanka - the next worst-affected country with a death toll of about 40,000 - a disaster management agency was set up after the 2004 tsunami.
The country's early warning towers were completed in 2007 and the agency also send alerts to phone users to make sure that any warning is well communicated. Regular tests are carried out and full rehearsals are done on a regular basis.
Such multi-faceted warning systems are much-needed progress said Srinivasa Tummala, an oceanographer who heads the Indian Ocean Tsunami Warning and Mitigation System (IOTWMS) that was established in 2013 with the aim of promoting and developing its 28 member states' tsunami warning and mitigation capabilities.
"I think the Indian Ocean is much safer against the threat of tsunami than it was in 2004," he says.
While it is hard to predict if a disaster of such scale could hit the Indian Ocean region again, the surrounding nations are now entering the so-called "last mile" in building their warning systems or "community readiness", Tummala said, including making sure the tsunami-prone communities are well prepared and drills are conducted frequently.
Experts are looking into new technologies like mobile apps and the Global Navigation Satellite System (GNSS) network to enhance the system. But the low number of tsunami buoys and other detection equipment as well as an absence of real-time data sharing are "gaps" that need to be filled to improve the tsunami warning system, added Tummala.
Threats like the twin tsunami triggered by underwater landslides in Indonesia's Palu and Banten province due to a volcano eruption this year which were fast-moving, are new challenges the early warning system also need to take into account.
In India's worst affected area, Nagapattinam, new tsunami early warning systems and mobile apps were rolled out to alert residents. Of the more than 12,000 people who died in the 2004 tsunami in India, more than 6,000 of them were from in the southern Nagapattinam alone.
In Thailand, almost 6,000 people, among them about 2,000 foreign tourists, were killed when the tsunami struck 15 years ago. Early warning system towers and tsunami evacuation centre were erected after 2004 but some local residents remain sceptical about the effectiveness.
Prayoon Chonkraichak from Ban Nam Khem village hopes that the authorities will consider utilizing the evacuation building for other purposes as one of the ways to boost their "confidence" towards the facilities should another big wave hit.
On a sleepy Wednesday morning, the Thai national anthem was played as a test over the tsunami early warning system, the sound echoing sombrely as local residents stand in pensive silence, hoping to not hear the speakers be used for a real life emergency the likes of which washed over these lands some 15 years ago on Dec 26, 2004.