This documentary about the 2004 Boxing Day tsunami is horrifying, heart-rending and essential. It’s a privilege to hear some of these survivors speak about the experience

What more can be said about the worst natural disaster of our lifetimes? The 2004 Boxing Day tsunami, caused by an earthquake (the third-most powerful in history) off the coast of Sumatra, Indonesia, affected 14 countries around the Indian Ocean basin and killed more than 225,000 people. As an incomprehensibly massive event that occurred before smartphones were ubiquitous, the tsunami is very well documented and yet not: the mess of scrambled pictures has been picked over many times.

Tsunami: Race Against Time, a four-part documentary that flies by, reshapes the catastrophe into an anthology of gripping stories, capturing the carnage and stirring, moving tales of survival. The contemporary footage – walls of water silently approaching beaches, torrents raging through buildings, people hurt or dead in the aftermath – has been painstakingly resourced and expertly linked together, but it’s the testimonies of the survivors that stick.