The 34-year-old singer was on his way to a concert in Manchester, north west England, with his The Script bandmates Mark Sheehan and Glen Power when they saw a car spin off the road, and felt compelled to save the driver because of a recent car accident his sibling had.
Recalling the terrifying incident at the Capital Jingle Bell Ball show at London's The O2 on Saturday, Danny told BANG Showbiz: "We saw the car hit the barrier then the car started spinning and spinning, and all the debris from the car was flying everywhere, so literally before it had stopped spinning we had 999 on the phone because obviously we were the first ones at the scene.
"We ran over, next we asked if she was OK, tried to open the door but the door wouldn't open because it was jammed, and then there was smoke coming out of the car. Funnily enough, a month ago my sister's car burst into flames on the highway so I was just thinking of that. Obviously my sister was very lucky to get out of that alive, so I was just thinking, 'Let's get her out of the car,' so we got her on the side of the road and gave her a drink of water and waited for the emergency services to come along."
The 'Superheroes' singers downplayed their hero status following the incident saying, "anyone would have done the same", but Danny admitted he was surprised other vehicles didn't stop to offer assistance.
He added: "The funny part was people were tweeting saying, 'I think I've just seen The Script darting across the road,' and I was like, 'Yeah well what are you doing tweeting, why don't you come and help?!'"