Sirens sounded in Indonesia today as survivors and relatives of victims began events of honor and remembrance of the estimated 220,000 people who perished when a devastating tsunami hit the Indian Ocean countries exactly 20 years ago.

THE 9.1 magnitude earthquakeoff the western coast of the Indonesian island of Sumatra on December 26, 2004., generated huge waves that pounded the Indonesiathe Sri Lankathe Indiathe Thailand and nine other countries watered by the Indian Ocean — casualties were reported as far away as Somalia.

See shocking images from the disaster

tsunami

tsunami

tsunami

In the Indonesian city of Banda Aceh, an official ceremony at the Baiturahman Grand Mosque was the first of a series of commemorative events in Asia. The siren sounded, for three minutes, just as a very strong earthquake caused the biblical tsunami.

tsunami

Other ceremonies, notably memorial services, are expected to begin across the region, and were also being planned overnight stays on beacheswhere many foreign tourists, who had gone to celebrate Christmas in sunny destinations, died.

The hardest hit area was its northern part Sumatra. There the lives of 120,000 people were lost, most of them a total of 165,708 dead that Indonesia mourned.

In Thailandwhere they lost their lives over 5,000 people, more than half of the victims were foreign tourists, while another 3,000 people had been declared missing.

At Sri Lankawhere they lost their lives over 35,000 people, relatives of victims were expected to board the Ocean Queen Express train and head to Peraliya, 90 kilometers south of the country’s capital Colombo, where waves swallowed train cars, killing some 1,000 on board.