Cooper Appleyard is a fit, healthy and active eight-year-old boy with no history of heart problems.
But late on Monday, during a dance class at the Sylvania Heights community centre in Sydney, his heart stopped.
While the eight-year-old is expected to survive, his close call has prompted a plea from his parents to ensure similar cases don't end in tragedy.
"You don't think it's going to happen to you at all, or anyone in your family," Cooper's father John Appleyard said.
Doctors at the Children's Hospital say the first few minutes of anyone going into cardiac arrest are crucial and that Cooper's life may well have been saved by a nearby nurse who was able to perform CPR.
"We owe her our son's life and we owe all the rescue workers his life," John said.
Children's Hospital emergency specialist Dr Donovan Dwyer said: "Basically 10 minutes is all you have."
"And the chances of responding to electricity gets less and less the closer you get to the 10-minute mark."
There are calls for defibrillators to be installed in sporting and exercise venues to reduce the risk of tragedy occurring.
"We've actually had a defibrillator donated to the dance school this morning by the Mark Arcuri Foundation who have a charter of putting defibrillators in sporting clubs across the state," John said.
The foundation was established following the death of 15-year-old Marc Arcuri, who suffered sudden cardiac arrest while playing soccer in June 2014.
Cooper was practicing for an end of year concert when he went into cardiac arrest.
"Apparently he landed the barani [an aerial flip] and then the teacher looked away to look at another child, and someone yelled out to him, 'Cooper's collapsed'," Cooper's mother Kylie said.
He remains in a critical but stable condition and is expected to make a full recovery.