Dreamworld's parent company Ardent Leisure could be fined up to $3 million if it is prosecuted and found criminally liable over the theme park ride tragedy in 2016.

Key points: Ardent Leisure has been referred to the Office of Industrial Relations

Ardent Leisure has been referred to the Office of Industrial Relations The maximum penalty for a serious Workplace Health and Safety breach is up to $3 million

The maximum penalty for a serious Workplace Health and Safety breach is up to $3 million The coroner found Dreamworld had a "systemic failure" in all safety aspects

An inquest into the deaths of Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi revealed a litany of failures at the Gold Coast theme park dating back decades — including "shoddy" record keeping and safety systems that were "rudimentary at best".

In handing down his findings on Monday, coroner James McDougall said he suspected Ardent Leisure "may have committed an offence under workplace law" and referred the company to the Office of Industrial Relations to weigh up the case.

Industrial Relations Minister Grace Grace said an experienced independent prosecutor would examine the coroner's findings and material to determine what — if any — breaches have occurred.

"We will allow them to do their work," she said.

"It depends on the category, whether it is seen as reckless or serious breaches, but [penalties] range from a maximum of $1.5 million to $3 million [in] fines, as well as for individuals up to about $600,000 and possible jail as well."

The four victims were killed when their raft on the Thunder River Rapids Ride collided with an empty vessel and flipped in October 2016.

The inquest heard a water pump feeding the ride had broken down, causing water levels to suddenly drop.

The coroner found no evidence a thorough risk assessment of the Thunder River Rapids ride was ever carried out. ( AAP: Dan Peled )

Mr McDougall said if a qualified engineer had properly inspected the ride, the accident could have been prevented and it would have been shut down.

"It was simply a matter of time," he said.

"That time came on the 25th of October 2016."

He said there was no evidence a thorough risk assessment of the ride was ever done.

Mr McDougall also noted a lack of basic, modern safety controls and automation placed a "significant and unfair burden" on ride operators to observe and respond to situations.

"Such a culpable culture can exist only when leadership from the board down are careless in respect of safety," he said.

He acknowledged significant changes have been made at Dreamworld in the wake of the incident but made several broader, industry recommendations including that there be changes to the regulatory framework to include annual risk assessments of rides.

He also recommended the issue of a shortfall of experienced ride engineers be addressed.

Ardent Leisure's chairman Gary Weiss said the company was committed to implementing the coroner's recommendations and said safety was the number one priority.

"The coroner's report does not mark the beginning of change at Dreamworld, but rather represents a very important milestone in a continuous improvement journey for safety at Dreamworld that is ongoing," he said.

"They are proactively focused on continuous improvements to safety across the park, in the areas of ride safety and reliability, training of ride operators, emergency management procedures, safety management systems and safety governance."

Mr Weiss was appointed chairman of Ardent Leisure in September 2017.

A memorial garden will be built at Dreamworld to honour the four victims and those impacted by the tragedy. ( ABC News: Ashleigh Stevenson )

He said following the incident, the ride was closed, dismantled and removed from the site out of respect for the victims.

Many of the families and first responders have been compensated through private settlements.

A memorial garden will be built at Dreamworld to honour the four victims but a timeline on its construction is yet to be finalised.