The mother of a teenage boy who suffered a heart attack on a bus has thanked a mystery woman who helped keep her son alive saying she is an “angel”.

Sporty Frankie Quinn, 16, collapsed as he travelled home on the 267 bus, shortly after a visit to the gym last Saturday afternoon.

The heart attack hit the keen cricketer with such force that his heart stopped and passengers rushed to his aid.

A woman gave him mouth to mouth resuscitation, while Frankie’s former school pal, who was also on the bus, took his phone and called his parents. The teenager is now recovering in hospital where he is in a critical but stable condition.

His mother Cathy Quinn said: “We’re entirely in this woman’s debt. She was in the right place in the right time.

“If she hadn’t been there we wouldn’t have our son here today - she’s our hero, she’s an angel. You can’t help but think what if?”

“Frankie’s school friend was fantastic calling us. We were able to drop everything and get to the scene.

“It was a scene I never, ever want to see again.”

Frankie - who is a member of the Twickenham Cricket Club, based on Twickenham Green, and plays for the colts team - had been due to play in a match on Saturday afternoon in Teddington but on discovering it had been cancelled had gone to the gym.

After finishing his session at the Fountain Leisure Centre in Brentford, the Hounslow Manor pupil boarded the bus at about 2.30pm to travel to his nearby home. Minutes later he suffered the heart attack.

Mrs Quinn said: “For the first 48 hours we weren’t sure if he was going to pull through - it was the worst 48 hours of my life.

“He’s a fit and healthy boy, who’s hardly had a day off ill in his life.

“In the last 48 hours we’ve heard he’s going to live. We’re at a very positive point.

“It’s going to be a long journey but there’s light at the end of it.”

She said Frankie was now at the Royal Brompton Hospital in Chelsea, which specialises in heart conditions.

Mrs Quinn praised the “brilliant” care Frankie received by both the paramedics and the hospital staff and said the incident had shown her the “unbelievable humanity” that exists.

She said her son was undergoing tests to find out the cause.

Secretary of Twickenham Cricket Club, Dan Hough, said: “He's the nicest bloke in the world and a promising cricket player.

"I was completely amazed when I heard, he's the last person I'd have expected this to happen to."

Do you know the mystery life-saver? Call Joanna Kilvington on 020 8744 4272.