On 26 December 2004 an English girl, Tilly Smith, was walking on a beach with her family in Thailand. When they went down to the sea, Tilly saw that something was wrong. ‘The water was all frothy,’ said Tilly. ‘It was bubbling.' Tilly remembered a short film her class had seen at school about a massive wave called a tsunami. In the film the sea became frothy just before the tsunami struck. Tilly knew that a tsunami was coming. She began to scream at everyone to get away from the beach. Minutes later, the Great Indian Ocean tsunami struck the coast.
The tsunami had incredible power. It reached a height of 15 metres and smashed through hundreds of towns and villages in 13 countries. It drowned many people in their homes or on the beaches. It dragged many others out to sea. It destroyed property from Africa to Thailand. In total, more than 228,000 people died and millions were left homeless.
Tsunamis are usually caused by earthquakes under the sea. The earthquakes cause giant waves to travel outwards in all directions. The waves can be 30 metres high and travel as fast as 750 kilometres an hour. When they reach shallow water they slow down, but they can grow even bigger before they smash into the coast.
The Great Indian Ocean tsunami destroyed everything in its path. But the people beach on the beach with Tilly Smith that day were lucky. They listened to her and all ran to higher ground. None of them were killed. Tilly survived and returned to her school in the UK to tell her class the terrible story.