On the morning of 26 December 2004, Tilly Smith was with her parents and younger sister on the Mai Khao beach in Phuket. Ten years old, blond hair falling on her shoulders, Tilly looked jolly and fresh as she smiled in the sun. She had good reasons to be happy, thinking of the damp, cold England she had left behind. As mother and daughter went down to the water, Tilly noticed that the sea looked bubbly and frothy like on the top of a beer. This image triggered some recent memories in her mind. Two weeks earlier, during her geography class at Danes Hill School in Oxshott, Surrey, Tilly saw a movie about the Hawaii tsunami of 1946. She recognized the same warning signs: just minutes before the deadly wave hit, the water had begun to form bubbles and turn foamy, so very much as it did now.