His devastated mother says the accident led to his medical problems.
Police were called to the pool at 5pm yesterday after receiving reports a boy who had been visiting the facility with his carer had assaulted an employee.
Witnesses allegedly had to hold Pono Wairua Aperahama down until they arrived, by which time they found him in a serious condition.
The boy was treated at the scene by paramedics and then taken to John Hunter Hospital, where he later died.
Pono's mother Terina Abraham said she was organising to fly to Sydney from New Zealand.
"That is the plan to come over to Sydney. We are not decided yet as to where my son will be laid in his final resting place," she said.
She said that Pono's brain injury from the bike accident led to his medical problems.
Now, after fighting to recover for years, he has lost his life.
"Health issues were caused by his accident. He was perfectly healthy otherwise. He was born the smallest of my six babies and the easiest. Not much pain at all he slid out ... I could have had 10 of him if I knew birth was that easy," she said.
"My heart has been pulled out of my body and thrown into pieces on the ground ... I am speechless.
"I also had to fly from New Zealand to Australia when he had his accident.
"My king was the love of my life and my everything. He made me the person I am today.
"The fight he endured just to live. He made me realise anything in life is possible if you want it so much."
A heartbroken friend this afternoon said that Pono was a "cheeky" fella who was "always smiling".
"He was a fighter. His tough spirit got him through a lot. He never gave up and always had a smile on his face," the friend told The Daily Telegraph.
The friend confirmed he had been in a bike accident years earlier which put him into intensive care at The Children's Hospital at Westmead.
"He was riding a bike when a car hit him," they said.
"It was horrible. He was (in ICU) for quite some time."
Newcastle Assistant Commissioner Max Mitchell said the incident was tragic and the boy was self harming after suffering a medical episode.
He had a pre-existing condition and had been at the pool with a carer.
Assistant Commissioner Mitchell said there were reports the teenager was punching himself to the head and even smashing himself into the concrete.
"What is alleged to have occurred is the male was punching himself to the head area," he said.
Family and friends, many of whom are based in New Zealand, have paid tribute to the teenager this afternoon on social media.
One friend wrote: "You'll always be remembered bro. Not for what happened but for who you are as a person and friend. I wish we got to have that catch up we spoke about."
Another said: "Rest easy my brother. I will always remember you."
One neighbour, Susan Clark, who witnessed the incident told The Daily Telegraph she saw eight people trying to restrain Pono from her home.
"It is disgusting to have that pool open eight hours after a 17-year-old was killed," she said.
"Eight people were holding down a 17-year-old. It was traumatic.
"We saw a paramedic on top trying to bring this child back to life.
"What happened that it got to that point where the child got into cardiac arrest?
"I feel for the family."
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