Tsunami-hit nations will next week commemorate the more than 220,000 people who died in the Boxing Day disaster two decades ago, when huge waves tore into coastal communities around the Indian Ocean.
Beachside memorials and religious ceremonies will be held across Asia in Indonesia, Sri Lanka, India and Thailand, which were the worst hit by one of the deadliest disasters in modern history.
On December 26, 2004, tsunami waves as high as 30 metres (98 feet) in some areas wiped out coastal areas, splintered families, left thousands homeless and killed tourists on their winter breaks to palm-fringed beaches.
"My children, wife, father, mother, all of my siblings were swept away," said survivor and fisherman in Indonesia's Aceh province Baharuddin Zainun, 70.
"The same tragedy was felt by others as well. We feel the same feelings."
An undersea 9.1-magnitude quake caused the biggest faultline fracture ever recorded, sending giant waves hurtling towards coastal communities around the Indian Ocean basin.
The seabed being ripped open pushed waves at double the speed of a bullet train, crossing the Indian Ocean within hours without warning.
A total of 226,408 people died as a result of the tsunami, according to EM-DAT, a recognised global disaster database.
In Indonesia, where more than 160,000 died, mourners will gather in Banda Aceh for a series of ceremonies, starting with a moment of silence shortly before 8 am local time (0100 GMT) when the disaster struck.
Government officials, NGO representatives and members of the public will visit a mass grave in Banda Aceh where nearly 50,000 bodies are buried, before an evening mass prayer at the city's grand mosque.
In Sri Lanka, where more than 35,000 people were killed, a rebuilt express train hit by the giant waves 20 years ago will ride from capital Colombo to the same spot at Peraliya where it was ripped off the tracks.
A brief religious ceremony will be held with relatives of the dead from the incident that killed about 1,000 passengers, as well as residents who got onto the train after the first wave inundated the low-lying area.
Buddhist, Hindu, Christian and Muslim ceremonies will also be held to commemorate victims across the South Asian island nation.
In Thailand, where official figures say more than 5,000 were killed, around half of them foreign tourists, and 3,000 left missing, hundreds of people are expected to attend a government memorial ceremony set for December 26.
Among those invited are representatives of the foreign countries whose tourists made up around 2,500 of the dead.
In a hotel in Phang Nga province, there will be a tsunami exhibition, a documentary screening and introductions by government and UN bodies on disaster preparedness and resilience measures.
Local residents and mourners from across Thailand are likely to hold unofficial candlelit vigils all along the beach.
A commemorative "walk-run" set for December 27 will begin at the Ban Nam Khem Tsunami Memorial Park, a coastal garden with a Buddha statue and a curved concrete wall representing a wave, before stopping at the nearby Tsunami Museum.
Nearly 300 people were killed as far away as Somalia, as well as more than 100 in the Maldives and dozens in Malaysia and Myanmar.
There was no warning system in the Indian Ocean in 2004 but today a sophisticated network of monitoring stations has cut down warning times.
"It is important for all of us to know, disseminate and simulate (disasters)," said Indonesian teacher Marziani, who goes by one name and who lost a child in the 2004 tsunami.
"If we had known back then, the mountain wasn't far, we could have run from it."
