And his former wife Kim Dorsett says she is still waiting to hear the words "I'm sorry we did this".

Kate Goodchild and Luke Dorsett, and Luke's partner Roozbeh Araghi, were among the four people killed in October 2016 when the ride suddenly lost water volume and "systemic" safety failures occurred.

The coroner, James McDougall, found there was no proper engineering oversight, and safety and maintenance systems were described as "rudimentary at best".

Ms Dorsett says there was nothing surprising about the scathing coronial findings on Monday that the Gold Coast theme park had failed in all aspects of safety resulting in the deaths of four people.

Queensland's industrial regulator is now considering whether the park's owner Ardent Leisure should face criminal charges that could result in fines of up to $3 million and expose individual executives to hefty fines or even jail time.

Ms Dorsett says coroner James McDougall exposed safety failing after safety failing as he delved into the tragedy, and the findings were entirely unsurprising.

"It was something that we heard bit by bit, add-on by add-on, every day - that the policies and procedures just weren't being followed," she told the Nine Network on Tuesday.

"As the coroner said yesterday they couldn't be followed because people didn't know what they were."

Ms Dorsett said the names of her children and the other two victims must never be forgotten.

For her, every day spent in the inquest, listening to confronting evidence, was a way to give her lost kids a voice.

"I always felt that while I was there, they were there. I never want those four people to be forgotten. That's what this is really about."

Ms Dorsett said Ardent Leisure was now in "a world of hurt" and it's up to authorities what happens next, but added: "I don't think it's over for them".

"They have said they're sorry for the circumstances that we find ourselves in. I have never actually had an apology: 'Sorry you are now missing three important people out of your lives', yeah."

"I have never actually had 'I'm sorry we did this'."

On behalf of Mr Goodchild, Canberra barrister Steven Whybrow read a prepared statement to the packed inquest in which he hoped Work Health Safety Queensland would launch an independent investigation.

"The loss of Kate, Luke and Roozi has absolutely devastated our family," he said. "We will never be whole again. To say that we loved them is trite - we adored them.

"It has now been over three years since they were so needlessly taken from us. There is not a moment when we do not wish they never set foot on that ride."

He said that he hoped his children had not "died in vain" and "if anything good can come out of this, we hope that today's findings will ensure that no other family will ever have to face what we had to face".

The death of Kate Goodchild left two young children without their mother.

"Kate was the mother to two beautiful young girls, Ebony and Evie, whose lives have forever been changed. Ebony was 12 when her mother died; Evie, a mere eight months," he said.

He described how his son, Luke, had been in a loving relationship with his partner, Roozbeh Araghi, for 10 years.

"Luke and Roozi were both well known in the Canberra community, as advocates for a range of community-based initiatives," he said.

"If someone needed help - Luke and Roozi would provide it. They both thought of others before they thought of themselves."

Luke Dorsett and Kate Goodchild had both been employed by the Department of Human Services.

Following the tragedy, Queensland introduced new safety regulations for amusement rides, including mandatory major inspections of rides by qualified engineers every 10 years and improved training for ride operators.

The state also tightened workplace health and safety prosecution laws.

The park's owners, Ardent Leisure, issued a statement extending its sympathies to the families and friends of the victims of the tragedy.

It says it will create a memorial garden at the theme park to honour the victims and reaffirmed its commitment to implement the Coroner's recommendations relating to Dreamworld operations.

Coroner James McDougall has referred Ardent Leisure to the Office of Industrial Relations for possible prosecution under workplace laws.

External engineer, Tom Polley, has also been referred to the Board of Professional Engineers for failing to properly inspect the ride.

All four victims died after being flung into a mechanised conveyor when their raft collided with another and partially flipped after the water pump failed, causing water levels to drop.

The malfunction was the third that day and the fifth in a week, and no automated shutdown function was installed despite recommendations.

Ms Low's husband Mathew has been scathing towards the theme park operators, saying: "Dreamworld was a catastrophe waiting to happen because of their barefaced disregard for safety and maintenance".