The coronial inquest into the 2016 malfunction of Dreamworld’s Thunder River Rapids ride has begun, as authorities work to determine what caused the mechanical error which lead to the deaths of four people.

The Courier-Mail reports the Southport court room has already heard startling evidence about the ride’s chequered safety history, which raised concerns even before the tragic deaths of Cindy Low, Kate Goodchild, Luke Dorsett, and Roozi Araghi.

Low, Goodchild, Dorsett, and Araghi were killed when the raft they were riding collided with one in front and flipped backwards.

The inquest has heard that a 2001 malfunction resulted in the collision of several of the ride’s rafts, and that emails between staff included one admitting “I shudder when I think if there had been guests on the ride.”

It has also been heard the ride malfunctioned twice in the hours before the tragic incident, and that engineering staff didn’t attend the site the second time it happened.

Instead, Detective Sergeant Nicola Brown said the south water pump – which failed moments before the deadly incident – was simply reset without further investigation.

Det Sgt Brown also said one of the ride’s main operators was told there was an emergency stop button which would cease its operation in two seconds, but that it was unmarked – and that staff were advised “not to worry about” it as it was rarely needed.

Police have not recommended any criminal charges be laid against individuals as a result of the incident, but the inquest will attempt to determine why the pump failed so catastrophically, and what can be done to prevent similar occurrences from happening in the future.

The inquest will continue over the next fortnight.

Image: Jono Searle / Getty Images