This was in Aceh, Indonesia, in 2004, and the person is my friend, Dewi. In 2004, Dewi was living with her parents and her sister in their little house in downtown Banda Aceh, not far from the sea.

When the tsunami hit, it was a Sunday morning and Dewi was still in her pyjamas. Someone told them the sea was coming, and she and her family ran to the mosque – the highest nearby building. They made it just in time.

As the tsunami surged in, the water rose, nearly to the level of the mosque’s roof. They were on the roof for hours, she was never sure how long, crammed together with everyone else who made it. There were people in the flood water, and Dewi’s father spent most of his time trying to reach into the swirling water rushing past to pull out anyone still alive.

She remembered yelling at him to be carefulhe was reaching so far out to try and rescue people, she was terrified he was going to fall in. Meanwhile she was holding and trying to comfort an eight-year-old girl who had become separated from her parents and was bleeding heavily, eventually to death.

Dewi told me this story as we sat in a car, driving through the middle of the devastated tsunami zone on our way to a camp. She was really matter of fact, but I was a snivelling wreck. I met her dad later as well. He was a really nice man, totally unassuming, a low-level civil servant in the local bureaucracy. You’d never have guessed what he did.

She got a job with an aid agency, and she’s still a friend. We’ve never talked about it since, but I’ve never forgotten it. Without her dad, there would be people dead who are alive today. And without her, a child would have died all alone.

2012 Thomson Reuters Foundation