Tidal waves wash through streets in Maddampegama, Sri Lanka, on December 26, 2004. (Photo: AP Photo/Gemunu Amarasinghe)

On December 26, the worst earthquake in 40 years shook the bottom of the Indian Ocean near the coast of Sumatra. Within hours, a wall of water washed over the shores of nearby countries, destroying villages and pulling hundreds of thousands of people into the sea.

Now the world must help the region's many homeless survivors. You can get involved. First, read through this report to learn more about the disaster. Then visit the American Red Cross, UNICEF, and Save the Children to find out what to do.

Learn more about the tsunami by reading our articles about:

the latest news from the region;

relief agencies and how you can help them;

how relief agencies work;

American officials visiting the devastated countries;

why many animals knew that the quake was coming and ran for safety;

and where in the world the tsunamis struck.

Teachers—don't miss our Teacher Tips page, for more information to help you in your classroom.

Banner photos: Richard Vogel/AP Wide World; Binsar Bakkara/AP Wide World; Dennis M. Sabangan/AP Wide World/EPA