WHAT HAPPENED?

* On October 25, 2016, Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi were killed when a water pump on the Thunder River Rapids Ride malfunctioned, causing water levels to fall dangerously low.

* Their raft collided with another after becoming stuck in the low water and partially flipping, flinging the group into the mechanised conveyor that moved the rafts.

CRIMINAL INVESTIGATION

* In October 2017, police declined to file criminal charges against Dreamworld staff over the disaster.

INQUEST

* On June 18, 2018, coroner James McDougall launched an inquest into the tragedy.

* The inquest wrapped up after 31 days of testimony that savaged the theme park's reputation.

* It unveiled a litany of problems and was heavily critical of Dreamworld's training systems.

FINDINGS

* In February 2020, Mr McDougall referred Ardent Leisure to the Office of Industrial Relations.

* He said there was a "systemic failure" at Dreamworld in all aspects of safety.

* Mr McDougall found there had been no thorough engineering risk assessment of the Thunder River Rapids Ride in the 30 years it was open to the public.

* He said Dreamworld's "frighteningly unsophisticated" safety procedures were "rudimentary at best".

CHARGES LAID/GUILTY PLEA

* On July 21, 2020, Ardent Leisure was charged and pleaded guilty to three counts of failing to comply with health and safety legislation, and exposing individuals to a risk of serious injury or death.

SENTENCING

* Southport magistrate Pam Dowse on Monday fined Ardent $3.6 million, saying the company had failed in its primary safety duty to the public.

* The company knew of the risk of pump failure and the risk of rafts overturning before the accident, she said.

Australian Associated Press