Luke Simon, who survived the devastated 2004 Boxing Day tsunami which killed his brother, has shared the haunting two words he heard moments before.

On 26 December 2004, Amber Owen, from Milton Keynes, was on holiday in Phuket when a magnitude-9.1 earthquake struck under the sea in northern Indonesia. It claimed the lives of 230,000 people, but she was taken to safety by elephant Ningnong, who she was riding at the time the first wave hit.

Tsunami and earthquake data still isn’t shared widely around the world. Local authorities and experts often don’t communicate the risk to residents of flood-prone communities.