Ten years ago the first liver transplant on a child in New Zealand was performed.
Yesterday a playground full of laughing children was proof that the operation had changed lives.
About 150 people were at Butterfly Creek near Auckland Airport to celebrate the milestone.
Among them was Sharon Morgan, who recalled when she was told her son Liam had 24 hours to live unless a suitable donor was found.
At the time 23 people had been tested but none was a match.
"It was a horrific time. Incredibly, our family friend was found to be a suitable donor at the very last minute," she said.
"The worst thing was not knowing what the future might hold - we just had no idea," said Mrs Morgan.
She emphasised how important it was meeting other families going through the same thing - people she calls her "liver friends".
"You become so close - it helps to stop feelings of isolation," she said, adding that Liam was now a healthy and happy 10-year-old.
He is one of 79 children who have received liver transplants in New Zealand since 2002. Fifty-five per cent of these have been from deceased donors, whose memory was honoured with the release of butterflies.
Samantha Sutherland, whose daughter Lara was given a liver when she was eight months old, said the memorial service was important for her family. "It's a chance to pay our respects and say thank you - where would we be without them?"
The event was organised by the Kids Foundation, which provides support to liver transplant children and their families.
The foundation is raising funds for a dedicated patient and family centre close to Starship hospital.
Foundation board member Katy Brown said the aim of the centre was to create a "home away from home".
"Transplant children sometimes have to be in the hospital for months and months," she said.
"Our centre would make life heaps easier for their families."