The tsunamis of Sunday 26 December 2004 caught many people unprepared and unaware in Indian Ocean countries. This unexpected event struck without apparent warning on a clear day; many local people and tourists were on the beach and some walked over coral reef flats as the water receded to investigate a hidden realm. Within minutes, a series of massive waves returned to carry them away and invade the land. The tsunamis resulted in more than 250,000 people killed or missing and caused massive destruction to coastal resources and infrastructure. Our focus in this book is on the impacts on the natural coastal resources, especially the coral reefs and associated ecosystems, and the responses by the international community. But we cannot ignore that far more damage was done to the lives of people of the region and the world.