LATEST: Police say it’s a miracle two children on the same ride which flipped and killed four adults in a tragic accident at Dreamworld on the Gold Coast survived.

Two men and two women died when the Thunder River Rapids ride malfunctioned yesterday.

Police confirmed this morning four adults and two children aged 10 and 12, were on the raft when it flipped, but the children managed to escape.

‘In terms of how they escaped, maybe through the providence of God or somebody from what I’ve seen almost a miracle that anybody came out of that,’ Queensland Police Commissioner Brian Codd said.

‘If we are gong to be thankful of anything, I am thankful for that.’

The Australian Workers Union says they raised safety concerns with Dreamworld 18 months ago about some of the rides.

Queensland branch secretary Ben Swan said it was important to get all of the facts as the coronial investigation gets underway. 

He said there had been concerns raised by members of some of the rides at the theme park.

‘I am aware that since at least April last year, we have on numerous occasions we have raised  serious issues about the operation and maintenance of a number of different rides,’ he said.

‘I can’t say if it includes this ride in particular, but there have been several concerns we have expressed on behalf of our members in the interest of their safety and the safety of the general public.’

Dreamworld victims Roozbeh Araghi, Luke Dorsett and Kate Goodchild. Photo: Fairfax/Facebook

In a statement, MP Alan Tudge paid tribute to two of the victims, Luke Dorsett and Kate Goodchild, who were employed by the Department of Human Services. 

‘Employees in my ministerial office and department are in shock and deeply distressed by the news of the loss of two of their colleagues.’

A coronial investigation into cause of deaths is underway.

Dreamworld CEO Craig Davidson said everything is being done to look into the tragedy. 

‘We recognise this event has affected the entire Dreamworld family, our local, communities, guests and the emergency services and other first responders,’ he said today.

Prime Minister Malcolm Turnbull has also expressed his condolences.

Click PLAY to hear from union secretary Ben Swan: