Among mourning ceremonies Monday on three continents, mass prayers were sung at mosques in Indonesia's shattered Aceh province, candlelight vigils held in chilly Stockholm and an achingly personal tribute — a bouquet of white roses — plunged into the sand in Thailand.
Survivors relived the awe they felt when the sea rose up and surged inland for miles with seemingly unstoppable force, carrying trees, houses, train cars — and thousands people — with it in a washing machine-like churn.
"I was not afraid at the time," said Muhammad Yani, 35, who scrambled the second floor of an Aceh mosque and watched waters full of people and rubbish roil past him. "I was more aware than ever that my soul belonged to Allah."
Like that of most survivors, Yani's family was devastated — both his parents and a younger brother were killed.
"It was under the same blue sky, exactly one year ago that Mother Earth unleashed her most destructive power upon us," Indonesian President Susilo Bambang Yudhoyono told a crowd of hundreds at a function in the provincial capital of Banda Aceh, provincial capital of Aceh province, which had 156,000 dead and missing.
He sounded a tsunami warning siren — part of a system that did not exist last year — at 8:16 a.m. (0116GMT), the moment the first wave hit, to herald a minute's silence.
A year earlier, a magnitude-9 earthquake — the most powerful in 40 years — ruptured the ocean floor off the Sumatran coast, displacing billions of tons of water and sending 33-foot waves roaring across the Indian Ocean at jetliner speeds.
At least 216,000 people were left dead or missing and nearly 2 million lost their homes in a disaster that still rends hearts.
The waves hit as far away as east Africa and swept a passenger train from its tracks in Sri Lanka, killing nearly 2,000 people in a single blow.
Entire villages in Indonesia and India were wiped off the map. The lobbies of five-star hotels in Thailand were left littered with corpses.
Todd and Nadim Everts returned to Phuket, Thailand with their three young children, where a year ago they had been vacationing.
"When you're with your kids and normally just listening to their laughter and their happiness, when you're with them in the water now as an adult, you constantly find yourself turning around and looking at the horizon over and over again, because you're just afraid of what could occur in the future," Todd Everts said on CBS News' The Early Show.
World leaders sent condolences.
In a written statement, President Bush said the U.S. remains committed to "helping the citizens of affected nations rebuild their economies, communities and lives," reports CBS News correspondent Peter Maer.
Former President Clinton, the U.N. special envoy for tsunami recovery, promised not to let the world forget its pledges of aid.
Indonesia on Monday tested its tsunami warning system for the first time. Alarms sounded in the Sumatran town of Padang, 620 miles south of Banda Aceh, sending residents fleeing for higher ground in a simulation.
"We knew it was just a drill," said Candra Yohanes, 55, who was among those who ran. "Still, when I heard the siren, my heart was pounding so hard."
Scores of powerful aftershocks have rumbled through the region all year — a chilling reminder that Sumatra is sited on one of the world's most unstable geological fault lines.
Somber ceremonies were held around the world.
In Sri Lanka, President Mahinda Rajapakse met with survivors near the site of the deadly train accident. Butchers hung up their knives to show respect for life, and Buddhist monks chanted prayers through the night.
Thousands of Indians attended an interfaith service at an 18th century church, then marched to a mass burial ground.
Sweden, Germany, Finland and other European countries held memorials to mourn their dead. The tsunami killed more than 2,400 foreigners, many of them European tourists, in Thailand.
Somalis gathered in mosques along the East African nation's coast to commemorate the 289 people who disappeared in the waves and to pray for the tens of thousands still homeless.
"It was so brutal, so quick, and so extensive that we are still struggling to fully comprehend it," U.N. Secretary-General Kofi Annan said in a videotaped message played in Banda Aceh.
The tsunami generated one of the most generous outpourings of foreign aid ever known some $13 billion in pledges. But frustration is growing among the 1.4 million people still living in tents, plywood barracks or with family and friends.
"You want to talk about changes, we've seen nothing," said Baihqi, a 24-year-old Acehnese survivor, waving a hand dismissively at the jumble of scrap iron and plastic sheeting that is all that remains of his neighborhood. "Many promises of aid, but that's all we get - promises."
The anniversary "just means we've existed for one year," he said.