Brave Andrew Johnston was visiting Co Donegal for the weekend when the dramatic events unfolded.
Having sold his tickets to the Longitude Music Festival, Andrew, 21, surprised girlfriend Rhiannon Donaldson with a weekend in the seaside resort of Buncrana.
But while driving to the town on the Inishowen Peninsula, the young couple’s lives would change forever.
After passing through Porthall just outside Lifford, Andrew noticed a commotion on the road ahead at the Suile Bridge.
He said he initially thought it was a car crash but never thought he would end up saving the lives of two people just moments later.
It was only later he would discover how a car with an elderly couple had plunged into the Suile Burn, which flows into the River Foyle, just before 6.30pm on Saturday evening.
He revealed: “I thought it was a crash but then I noticed this guy coming running towards me. He asked me if I could swim and brought me to the edge of the river.
“What I saw unfolding before me was the scariest thing I have seen in my life.
“I saw the wreckage of a car and a man, whose face was covered in blood, was standing on the top of an upturned car.
“I’m not a gold medal swimmer but I got out to him and asked him if there was anybody else in the car.
“He told me his wife was in the car. To be honest, it wasn’t the answer I wanted to hear but I knew I had to do something.”
For the next two minutes, the second year engineering student at the University of Ulster in Jordanstown, tried on FOUR different occasions to reach Mrs Loreta McKinlay.
On the first occasion, he simply didn’t take enough breath and had to return to the surface.
On the second Andrewm from Lurgan in Co Armagh, reached into the front passenger seat of the car but there was nobody there.
He resurfaced and asked Mr McKinlay where exactly his wife was in the car.
The terrified husband pointed to the rear passenger side where he had last seen his wife before the couple hit the water.
Andrew, assisted by Mr McKinlay, then jumped back into the water and managed to pull open the rear passenger door.
They initially had to discard various pieces of clothing and bags in the back of the car before hauling Mrs McKinlay onto the top of the car.
Andrew added “She was unconscious. Her lips were blue and I’d never seen anything like it in my life. It was so scary. I was surprised there was any breathing at all.”
Mr McKinlay then attempted to perform CPR on his wife.
Others from the riverbank had managed to get a garden hose from a passing motorist and threw it to the rescuers to use as a makeshift life-ring.
They managed to bring Mrs McKinlay to the riverbank but couldn’t get her to dry land as the banking was too steep.
A number of passers-by then managed to lift the stricken woman up onto the edge of the river.
The emergency services were contacted but Andrew said it was at least 20 minutes before an ambulance manager to get to the scene.
However, Andrew revealed that a paramedic did speak to those at Mrs McKinlay’s side as they changed her recovery position and stayed with her as she battled to live.
“It was the longest 20 minutes of my life. I know Donegal is a large place and I’m not having a go at the ambulance service but I thought they were never going to arrive.
“I did genuinely fear the worse for the poor woman but the paramedics were doing their best to help us on the phone before the ambulance arrived,” he said.
When the rescue services including fire tenders, Gardai and medical personnel as well as the Rescue 118 helicopter did arrive, Andrew went to change his clothing.
“I was absolutely soaking from the river and I went to change my clothes. When I came back they had put up a cordon and I could not get past it again.
“At that stage I thought I had done all I could and I drove on with my girlfriend,” he said.
Andrew went to stay at the Harbour Inn in Buncrana on Saturday night but kept an eye on social media to find out any news on Mr and Mrs McKinlay.
It was only yesterday that he realised that reports of the potentially tragic event were describing him as the mystery hero.
“I don’t want to describe myself as a hero. I just wanted to find out how the couple were. I’m hoping they will be okay.
“I don’t want to think what could have happened. A lot of people helped out on the day and I was just one of them,” he said.
In a lovely gesture to the reluctant hero, management at the Harbour Inn in Buncrana heard about Andrew’s amazing bravery and gave himself and his girlfriend a free two-night stay to use in future.
“I should have been at Longitude but sold my tickets and decided to come to Donegal. I even got off my part-time job a little early so I shouldn’t really have been passing by that river.
“Life works in mysterious ways,” added Andrew.
Well done Andrew.
Mrs McKinlay remains in a serious condition in Altnagelvin hospital.