'Someone will get seriously injured or killed': Mother's warning to Dreamworld two weeks before fatal tragedy

Tuesday's fatal tragedy at Dreamworld comes just weeks after one mother warned the park on Facebook about the impending possibility that "someone will get killed one day".

More than 30 detectives are looking into what caused one of the worst theme park disasters in recent memory are already focusing on the Thunder River Rapid Ride's conveyor belt.

But it was only two weeks ago that Gold Coast mother Tracey Christiansen wrote an ominous warning to the park's operators on Facebook, telling of dangers that were seemingly being ignored by staff.

Along with a laundry list of "operational issues", Ms Christiansen complained that one of her children's belt buckles had come undone while mid-air on the Claw.

Mother Tracey Chrisiansen's complaint contained an eerie warning. Source: Facebook

According to the post, the family encountered maintenance issues on some of the Dreamworld's best-known attractions including the Tower of Terror, the Wipe Out and the Puss in Boots ride.

"The kids get off The Claw and said one of their belt buckles came undone right up in the air," Ms Christensen wrote.

"I told the attendants, they didn't listen. I went and told the manager and he said he will call someone to go have a look, yet they continued to let people on the ride and keep operating."

Four adults were killed when the Thunder River Rapid Ride flipped on Tuesday afternoon. Source: AAP

After encountering the same line about "maintenance and operational issues" at several rides, the mother gave Dreamworld a two-star rating.

"Are you freaking kidding me?" Ms Christiansen wrote, her anger coming through clearly in the post that ended with an eerie warning.

"Someone will get seriously injured or killed one day," she said.

A number of people have stated the Thunder River Rapid ride experienced maintenance issues on Tuesday before tragedy struck.

More than 30 police detectives are investigating the accident. Source: AAP

Speaking on Sunrise, Queensland Annastacia Palaszczuk said countless people were in shock across the country as the investigation commenced.

"Police are doing everything they can to ensure that the investigation is absolutely thorough," she said.

More than 30 detectives have been on the scene since the accident occurred and will work late into the evening compiling witness statements, the premier said.

"But today, the focus will turn towards the actual ride itself and what policies and procedures were in place for that particular ride," Ms Palaszczuk said.

"We need to ensure this never ever happens again," the premier said.

Opened in 1986, Dreamworld's Thunder River Rapid ride had a fatal malfunction on Tuesday when one of the boats flipped, killing four adults.

Described as "family friendly", the six-person ride reaches speeds of 45 kilometres an hour, through man-made rapids

The park remains closed with no date set for reopening. Source: AAP

Since it opened on December 15, 1981, millions of people from home and abroad have visited Australia's largest theme park.

Today, Dreamworld could potentially face millions in compensation and lawsuits.

Park operators could be hit with the highest offence for workplace health and safety for reckless endangerment if found negligent.

Alison Barrett of Maurice Blackburn Lawyers told News Corp the maximum penalty a corporation faces is $3 million.

Individuals could be fined $600,000 or serve five years in prison.

"When accidents like this occur, generally negligence is revealed, and sometimes gross negligence," Ms Barrett told the Courier-Mail.

"What often is seen is a poor safety culture and poor behaviour in relation to safety," she said, adding that such a tragedy "isn't an act of God" or a "freak accident".

"They tend to occur because of a disregard of someone's safety."