When John O'Brien left his sleeping wife and baby to head off to work in the early hours of September 4, 2014, he had no idea it would be the last time he would see them alive.
Mr O'Brien had been living in an apartment with his wife Bianka and their 11-month-old son Jude on top of a Rozelle convenience store owned by Adeel Khan.
Unbeknown to the occupants of the two apartments upstairs, Khan had rigged up 10 petrol containers in the store, which he planned to set alight in order to make an insurance claim.
The subsequent explosion and ferocious fire caused the deaths of Bianka, Jude and another man, Chris Noble, who has been living next door to the O'Briens.
Khan was convicted of two counts of manslaughter and one count of murder, and was sentenced to 40 years jail.
Now, more than five years after the tragedy that tore apart his family, John O'Brien will honour his wife and son by holding a dinner to raise funds for children affected by homicide.
The Jude O'Brien Dinner will be held at Doltone House, Sylvania, on Thursday, March 5 - Bianka's birthday.
Channel Nine weather presenter Tim Davies will host the event and singer Mark Vincent will perform.
Money raised will go to Grace's Place, a world-first residential trauma centre for children affected by homicide which will be operated by the Homicide Victims Support Group.
Mr O'Brien, who now lives in Gymea Bay with his second wife Michelle Minehan and their two young daughters, says the group provided him with much-needed support following the deaths of Bianka and Jude.
"They work in with the police so [the police] gave my contact details pretty much straight to them and within 48 hours they rang me," he said.
"I wasn't really in the right head space so my brother took over contact.
"The Homicide Victims Support Group had already got my family and friends together and told them what they should expect, so my brother was with me all the time."
In those early days, Mr O'Brien struggled to process what had happened.
"I went to work [the day of the fire] with my phone and my wallet. When I came home I had nothing. No keepsakes. Nothing," he said.
With his home and belongings destroyed, the group arranged for Mr O'Brien to stay in a respite home south of Sydney, where he was able to gather his thoughts and begin the long grieving process.
That is when Mr O'Brien became overwhelmed with guilt that he hadn't been home to try to save his family, or that he hadn't investigated the strange smell his wife complained about, which turned out to be petrol.
He initially declined grief counselling, but later worked with a counsellor who had supported the families of the Bali bombing victims.
Gradually, Mr O'Brien accepted what had happened and let go of his guilt.
Michelle, who he already knew and had been assigned by NSW Police Media to help him draft a statement after his wife and son's death, was also there to offer support.
"She worked with the cops as well so she knew the whole case and the whole back story," he said.
It was during a recent discussion the pair had about how the Homicide Victims Support Group had helped get him through his darkest days that Mr O'Brien decided he needed to give something back.
He contacted the group's executive director Martha Jabour. She told him about the centre being built to support children affected by homicide.
"I thought, if it was so tough for me, I would hate to think how hard it would be for a child, so I just said 'What can I do to help?'," Mr O'Brien said.
The resulting dinner named after his son will be held on Bianka's birthday as a mark of respect to her.
Bianka had deep connections with Sutherland Shire, having grown up in Miranda, as well as St George, where she owned Ramsgate hair salon Urban Hair Culture at the time of her death.
"I would like to see everyone get behind it. It is a good way to remember Bianka on her birthday and raise money to support something positive that has come out of a pretty negative thing," he said.
Tickets are $185 each or $1800 for a table of 10. For details and tickets click here