Married father-of-two Geoff Maxwell, a retained fire-fighter and joiner with his family firm, was working in a house next to the road bridge when the alarm was raised.
After hearing cries for help from the girl’s mother, he ran down to the riverside, dived into the chilly waters and in a feat of endurance managed to bring the youngster ashore.
The missing man, who was also believed to have tried to save the girl, had by then vanished and was feared drowned.
Speaking afterwards at his home in Arkinholm Terrace, Mr Maxwell, 52, recalled seeing adults and a number of children going down to the riverside in swimming gear before the incident on one of the warmest afternoons of the summer.
He said: “Around 15 minutes later I heard screams, like kids playing in the water, but then the cries became more intense and I realised something was wrong.
“I dropped my tools and went out where I saw the woman, who I took to be the girl’s mother. She was crying ‘help, help’ and pointing to the water saying the two were in there.”
Mr Maxwell, who described himself as a poor swimmer, took off his boots, and used his fire service training to weigh up his options carefully.
But he said: “I then saw the lassie’s head pop up above the surface, coughing up water and crying for help. She was about seven or eight feet out, downstream of the bridge and I instinctively swam out to get her.
“I dived under the water and managed to pull her back up to the surface.
“By a stroke of luck she put her arms round my neck which left my arms free to swim towards the ledge at the bridge where I could see her mother with her hands held out to catch her.”
The firefighter described his ‘utter exhaustion’ after the incident but how adrenaline or other factors had given him energy.
He said: “On reflection I should have swam with the current with the girl towards a bank rather than against the current to the mother on a ledge at the bridge. However, she gave me something to focus on and that helped.
“Sadly I could see no sign of the man. The water was not clear and the pool below the bridge seemed to be about 16 feet deep.
“Having experienced the conditions I think the man must have become absolutely exhausted trying to save the girl. It’s an absolute tragedy but he deserves great credit for what he did to try to save her.”
The modest Muckle Toon native played down his own achievement stating that other people would have done what he did in the same circumstances.
He said: “After seeing that wee girl’s face coming out of the water I could not have lived with myself if I had done nothing.”
Mr Maxwell, whose wife is a nurse, was initially taken to the Cumberland Infirmary but was allowed home after being checked over by an ambulance crew.