A passer-by rescued a mother and her two children who became trapped on a muddy embankment after a canal burst its banks.
Julie Smith and her two boys, aged seven and 11, were walking by the Leeds and Liverpool Canal in Hunslet when it flooded on to the footpath.
Her youngest son was slipping into the water when dog walker Calum Strodder came to their aid on Tuesday.
She said Mr Strodder "saved our lives" but he "didn't think anything of it".
The 37-year-old said she and her sons, Ethan and Kieran, were terrified because the water was fast-flowing and they were struggling to keep their footing.
After spotting the family in trouble, Mr Strodder tied his dog Maggie to a lamppost and waded through the water before leading them to safety.
Although they chatted briefly afterwards, Mrs Smith did not get his name so started a Facebook appeal and managed to track him down.
"If Calum hadn't have come along God knows what would have happened. The boys were scared to death. All three of us are incredibly grateful for his kind actions."
Mr Strodder said: "I didn't think anything of it really. I just saw them in trouble and I was the only one around to help. I'm just glad Julie and her children are safe."