British brothers have spoken of “fighting for their lives” during the tsunami that killed their parents.

It has been 20 years since the disaster that killed more than 220,000 people after a massive earthquake measuring 9.2 to 9.3 struck the Indonesian coast.

The devastating tsunami of December 26, 2004 struck a dozen countries bordering the Indian Ocean, wiped out entire coastal communities, wiped out families and crashed onto tourist-filled beaches, with survivors floundering in a horror show filled with dead water.

Leonard Barratt, 50, and Catherine Mullan, 53, from Cornwall, were among those who sadly lost their lives in Thailand when waves of up to 30 meters hit.

Their children Louis and Théo were then 16 and 11 years old and were separated but managed to survive.

In a new National Geographic documentary, Tsunami: Race Against Time, the brothers talk about the traumatic experience.

Louis remembers “holding on to each other” and described the tsunami as “scary”.

He said: “We were going snorkelling… and then Dad came to our room to pick us up and say, there’s something going on on the seafront, to come and look.

Louis and Théo were 16 and 11 when the tsunami hit but managed to survive

In a new National Geographic documentary, Tsunami: Race Against Time, the brothers talk about the traumatic experience

Vacation homes destroyed by the tsunami are pictured on Phi Phi Island, Thailand, in 2004.

Unawatuna Beach, Sri Lanka, after the 2004 Indian Ocean tsunami

Debris is scattered where bungalows once stood on Phi Phi Island in Ton Sai Bay, 2004

“When we got there, we could see that the water had receded quite a ways, and you could just see sort of a bubbling sea in the distance, but no one knew what was happening at that point.”

He and Theo ran to lock their room and about 20 seconds later returned to find that “panic had set in”, before the water quickly overtook them.

“Theo and I were holding on to each other, and then the water got too deep, and we were at our depth, and then we separated, and then we both separated in the water.”

Fortunately, they then managed to find each other and set out in search of their parents.

The boys stayed in Thailand for several days before returning to the UK without their parents.

They were then adopted by a family in Cornwall.