The heartbroken father of two of the victims in this week's Dreamworld tragedy has spoken of the families' need to understand how their loved ones died.
Shayne Goodchild thanked Australians for their overwhelming outpouring of support after the horrific accident that killed four people at the Gold Coast theme park on Tuesday.
But Goodchild - whose daughter Kate Goodchild, 32, and son Luke Dorsett, 35, died in Tuesday's fatal accident - said understanding how a family holiday had turned so tragic was something the families need to know.
"Like everyone else in Australia we want to know what went wrong," he said.
"To say this is just not fair doesn't begin to express our despair.
"We want to know why our loved ones were taken away from us in such horrific circumstances."
Dorsett's partner Roozi Araghi, 38, and Sydney woman Cindy Low, 42, were also killed in the accident.
Goodchild's 12-year-old daughter Ebony and Ms Low's 10-year-old son were on the raft that flipped at the end of the Thunder River Rapids ride, but survived.
Flanked by his daughter's partner Dave Turner, who witnessed the tragedy, Goodchild said his granddaughter would need all the support and strength the family could muster.
He declined to comment on the response of Dreamworld or its parent compant Ardent Leisure, insisting the families would wait for the outcome of a coronial investigation into the accident.
After being criticised for a cancelled plan to open the park for a public memorial on Friday ahead of resuming operations on Saturday, Dreamworld announced the facility would remain closed at least until funerals for all four victims are held.
Dreamworld chief executive Craig Davidson said even when the park reopens, all attractions at the facility would undergo "internal and external safety audits" that would be peer reviewed.
Davidson attended a private memorial for the victims at the park alongside parent company boss Deborah Thomas and approximately 400-500 staff.
Thomas, who came under scrutiny for accepting an $843,000 bonus at Ardent Leisure's annual general meeting in Sydney on Thursday, laid a floral tribute to the victims at an ever-growing shrine outside the park's main entrance.
She apologised for any pain her, or the company's, actions may have caused the families following the tragedy.
"I would like to say that if I haven't handled it as well as I could - we thought we were doing the right things in terms of the way we approached it through the police - but if the families are watching, I have spoken to a number of them and we will look after them," Thomas said.
"I hope that this is the beginning of the healing process."
Queensland Police Commissioner Ian Stewart said the ongoing investigation at the accident site was proving complex.
"There are a range of specialists investigators, not necessarily from Queensland police services, but from other agencies that need to be engaged and they have been," Stewart said.
Dreamworld has also defended its safety record against criticism from the Australian Workers Union, which says it has been warning about problems at the park for years.
The theme park's management says the ride was inspected as recently as last month.
Queensland Employment Minister Grace Grace was among those who laid flowers for the victims outside the park's entrance.
Grace said the AWU's response was right."They did the right thing. They put in what their concerns were, whether anyone could have predicted this particular event happening is very difficult and, of course, those concerns should be raised," she said.