BANDA ACEH, Indonesia — Beside gentle seas, survivors, friends and family remembered the fury of the Indian Ocean tsunami that swept away more than 200,000 people in 12 countries one year ago today and laid waste to entire communities in one of the worst natural disasters in memory.

On Thailand's Patong beach, a man sat weeping in the sand before a gently lapping sea, a bouquet of white roses in front of him.

Ulrika Landgren of Malmo, Sweden, came to the Thai beach where nine family friends died.

"Somehow it's good to see this place," the 37-year-old said, tears leaking from behind her sunglasses.

The two mourners were among hundreds of Western survivors, relatives and friends of the dead who came to Thailand's famous beachfront where their loved ones disappeared.

On India's southern coastline, thousands of fishermen visited mass graves, sharing stories about lost families and friends.

"I searched for my daughter for hours but never found her. I don't know where she was buried," E. Jayaraman said today as he looked forlornly out to sea.

"The sea is like God to us. My wife will come later in the day and pray at the same site for peace to the soul of our daughter."

Last Dec. 26, the most powerful earthquake in 40 years ruptured the sea floor off Sumatra, displacing billions of tons of water and sending 33-foot-high walls of water roaring across the Indian Ocean at jetliner speeds. At least 216,000 people died or disappeared.

In Indonesia's Aceh province on Sumatra island, the closest land to the epicenter of the magnitude-9 earthquake, the president sounded a tsunami warning siren to start a minute's silence at 8:16 a.m. — the moment the first wave struck.

"It was under the same blue sky, exactly one year ago that Mother Earth unleashed her most destructive power upon us," President Susilo Bambang Yudhoyono said. "The assault began with a massive earthquake but ... that was only a prelude to the horrific catastrophe to come."

A silence was also observed in Thailand and Sri Lanka, where President Mahinda Rajapakse joined ceremonies near the site where the raging waves swept a passenger train from its tracks, killing nearly 2,000 people. Elsewhere in the country, butchers hung up their knives to show respect for life while Buddhist monks prepared to chant through the night.In India, thousands took part in interfaith prayers at an 18th century church, then marched to a burial ground for tsunami victims.In Thailand, some villagers refused to take part, saying the rites were expensive, inappropriate events designed to attract tourists and showcase the government.World leaders sent condolences.The tsunami swept away entire villages in Aceh and Sri Lanka, swamped five-star resorts in Thailand and surged into coastal communities from India to east Africa.On that day, Muhammad Yani clung to the second floor of an Aceh mosque, watching waters full of people and rubbish roil past him."I was not afraid at the time," said Yani, 35, who later learned that his parents and a younger brother were killed. "I was more aware than ever that my soul belonged to Allah."Indonesia, for the first time, tested its tsunami warning system in Sumatra today — a chilling reminder that the island sits on one of the world's most unstable geological fault lines. Scores of powerful aftershocks have rumbled the region all year."We knew it was just a drill," said Candra Yohanes, 55, who was among thousands of residents of Padang town who fled to higher ground on hearing today's alarms. "Still, when I heard the siren, my heart was pounding so hard."The true toll of the tsunami will probably never be known. Many bodies were lost at sea and population data in some places was destroyed.The Associated Press found in an assessment of government and credible relief agency figures in each country hit that at least 216,000 died or disappeared. The U.N. puts the number at least 223,000, although it says some countries are still updating their figures."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 today.The tsunami generated one of the most generous outpourings of foreign aid ever known. Some $13 billion was pledged to relief and recovery efforts, the U.N. says, of which 75 percent has already been secured.But the pace of reconstruction has been criticized, and frustration has grown with 80 percent of the 1.8 million people displaced by the waves still living in tents, plywood barracks or with family and friends.In Aceh, one survivor dismissively gestured at a jumble of scrap iron and plastic sheeting — all that remains of his neighborhood."You want to talk about changes, we've seen nothing," said Baihqi, 24. "Many promises of aid, but that's all we get — promises."Of the anniversary, he said; "It just means we've existed for one year. We're still around."The tsunami had the unlikely effect, however, of helping usher peace to the province.The government and separatist guerillas decided they did not want to add to people's suffering and ended a nearly three-decade civil war that left nearly 15,000 dead.In Sri Lanka, the waves had the opposite effect. Disputes over tsunami aid and an upsurge in violence have raised fears the island will return to civil war despite a 2002 cease-fire.