On December 26, 2004 a 9.3-magnitude earthquake off Indonesia's western tip generated a series of massive waves that pummelled the coastline of 14 countries as far apart as Indonesia, Thailand, Myanmar, Sri Lanka and Somalia.
Indonesia was the worst hit, with about 220,000 deaths. In Myanmar, the official death toll was 61, whereas independent media reports claim 90 were killed, with witnesses claiming the toll could have been as high as 600 deaths.
Among the victims across Asia were thousands of foreign tourists enjoying Christmas in the region, carrying the tragedy of an unprecedented natural disaster into homes around the world.
In Indonesia's Banda Aceh, a chorus of voices singing the Indonesian national anthem opened the official memorial at a 20-acre park. Banda Aceh was the main city of the province closest to the epicentre of the massive quake and which bore the brunt of waves towering up to 35-metres (115 feet) high.
"Thousands of corpses were sprawled in this field," Indonesian Vice President Jusuf Kalla told the crowd of several thousand - many among them weeping.
"Tears that fell at that time... there were feelings of confusion, shock, sorrow, fear and suffering. We prayed.
"And then we rose and received help in an extraordinary way. Help came from Indonesia and everyone else, our spirits were revived," he said, hailing the outpouring of aid from local and foreign donors.
Mosques also held prayers across the province early Friday while people visited mass graves - the resting place of many of Indonesia's 170,000 tsunami dead.
But a Red Cross display of hundreds of salvaged ID documents and bank cards, also served as grim reminder that many victims simply vanished.
In southern Thailand, where half of the 5,300 dead were foreign tourists, a smattering of holidaymakers gathered at a memorial park in the small fishing village of Ban Nam Khem, which was obliterated by the waves.
As the ceremony began, survivors recounted stories of horror and miraculous survival as the churning waters, laden with the debris of eviscerated bungalows, cars and boats, swept in without warning, killing half of the village's inhabitants.