Somehow two young children escaped the Dreamworld tragedy with their lives.
But both must now live with the trauma that their mothers were among the four people who died at the Gold Coast theme park on Tuesday.
Two women - 42-year-old Cindy Low and 32-year-old Kate Goodchild - died in the accident when a raft they were riding in on the Thunder River Rapids ride flipped backwards along with Ms Goodchild's brother Luke Dorsett, 35, and his partner Roozbeh Araghi, 38.
Ms Low's 10-year-old son and Ms Goodchild's 12-year-old daughter were in the raft but survived the incident.
Mr Dorsett and Ms Goodchild's mother, Kim Dorsett, said her devastated 12-year-old granddaughter was blaming herself for the tragedy.
"I have three children and have lost two of them... my whole family has been wiped out," she told The Courier-Mail.
"I have two granddaughters - an eight-month-old and a 12-year-old - and it truly breaks my heart to know that my eight-month-old is never going to get to know her mum."
Ms Dorset says she has been with her granddaughter all afternoon and all night.
"Like me, she is still coming to terms with it all but she is completely devastated. She is blaming herself for what has happened."
Ms Goodchild, her daughter, brother and Mr Araghi were on holiday from Canberra and did not know Ms Low and her son.
The local community expressed its grief on Wednesday, a floral tribute at the park's entrance growing from a handful of bouquets at the start of the day to a line of flowers stretching over 20m along a brick wall by the late afternoon.
The children who survived the accident were forefront in the minds of those who came to pay their respects, including Dreamworld chief executive officer Craig Davidson.
"These children will have our full support into the future," Mr Davidson said.
Queensland Police Assistant Commissioner Brian Codd says the children's survival almost defied belief.
"In terms of how they escaped, maybe through the providence of God," he said.
"From what I've seen [it's] almost a miracle that anybody came out of that. If we're going to be thankful for anything, I'm thankful for that."
The distraught family of Ms Low, a New Zealand expat living in Sydney, released a statement on Wednesday expressing their shock and sadness at the "catastrophic" event.
"The family are traumatised, and kindly request that their privacy be respected as they try to come to terms with this tragic loss," the statement said.
A team of 30 detectives as well as engineers and safety officials spent the day at Dreamworld as a coronial investigation continued.
The park will remain closed indefinitely during the investigation, with police only willing to say at this stage a malfunction in the ride appeared to have caused the raft carrying the six people to collide with another on the conveyor belt system, causing it to flip backwards.
Two of those killed were thrown from the raft, while the other two were trapped in the ride itself.
The Australian Workers Union, which represents Dreamworld staff, said it took serious safety concerns about maintenance and operating regimes to the park's owner Ardent Leisure as far back as April 2015.
The ride completed its annual maintenance in September.
There are also claims by park visitors the ride had malfunctioned at least twice earlier in the day.
Police have vowed to pursue anyone whose negligence contributed to the tragedy.
"We owe it to the deceased and their families, we owe it to the community of Queensland, to get to the bottom of what caused this," Asst Comm Codd said.
"If and where there is criminal aspects, including negligence, which warrants being pursued, we will do that."
Queensland Premier Annastacia Palaszczuk was among several community leaders to plead with holiday-makers not to abandon the tourism-dependent Gold Coast.
Concerned locals said they would return to Dreamworld when it reopens but it seems unlikely the 30-year-old river rapids ride will continue to operate.
NZN / Newshub.