>> A fun day out turning to tragedy at Australia's biggest theme park. Four adults killed when a river ride malfunctioned at Dreamworld on the Gold Coast, south of Brisbane.>> The thing flipped and obviously there were kids on board screaming while their mom was like trapped under. And yeah, I'd rather not talk about what I saw.
>> The Thunder River Rapids ride consists of six seater floats that follow a water course simulating river rapids. Dreamworld describes it as a moderate thrill attraction for those older than two.>> One of the rides had sustained a some sort of malfunction causing two people to be ejected from a ride, another two people were caught inside the ride, two males and two females.
>> The four dead were in their 30s to early 40s. Visitors at Dreamworld said they had seen repairs to the ride before the accident.>> I've been waiting there for about half an hour and engineers had to come. They drained all the water out and then had to refill it back up, and then we were allowed to go.
But yeah, we were stuck there for about 30, 40 minutes at least.>> The spokeswoman for the theme park was unable to confirm the reports. The tragedy ranks among the world's deadliest theme park accidents. Dreamworld remaining closed tomorrow as a mark of respect. The Australian Prime Minister, Malcolm Turnbull, said that there will be a thorough investigation to determine the accident's cause.