Queensland police say anyone who contributed to the deaths of four adults on a ride at Dreamworld will be held to account.
"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," Assistant Commissioner Brian Codd told reporters on Wednesday.
" If and where there is criminal aspects including negligence which warrants being pursued we will do that."
Mr Codd confirmed two girls, aged 10 and 13, were on the raft that flipped.
He said he'd viewed CCTV footage of the incident and it was miracle they had survived.
"Maybe through the providence of God or somebody, but it seems from what I've seen almost a miracle that anybody came out of that," he said
"If we're going to be thankful for anything, I'm thankful for that."
Police said some of the reporting regarding the victims had been wrong.
"There's been reporting of names, and family relationships...can I tell you firstly that some of that is inaccurate," Assistant Commissioner Codd said.
"I know how interested everybody is in the circumstances of the family.
"This is a real, you know, emotional and a human catastrophe. But I'm not going to compromise the courtesy and respect of the broader families by going into that detail at this stage."
Mr Codd said the ride remained a crime scene and would be closed for several days.
He said any evidence of negligence would be doggedly pursued, and the coronial investigation would no doubt take great interest in union claims about safety concerns raised with the theme park 18 months ago.
"We will be pursuing the full coronial process and that will examine things from the operational and engineering perspective, but where there's criminal aspects that include negligence that warrant being pursued - we'll do that," Mr Codd said.
He said maintenance would form a critical part of the probe, including any problems with the ride that had surfaced in the past.
"We have specialist engineers that will be attending today and will be examining certain componentry that goes with that ride," he said.
"There will be a broad range of things examined - policies, procedures, maintenance schedules - ... the make-up of the whole ride itself in terms of compliance."
Mr Codd said the accident happened when two rafts collided at end of the ride, around where people got off.
"... one has flipped backwards and it has caught and tossed some of the people that were on the ride backwards on the conveyor belt," he said.
"That's about as much detail as I can go into."
