Dreamworld witnesses tell of horror after four die on Thunder River Rapids ride

Witnesses to a horror incident on a ride at Dreamworld have described how people fled the park crying as the ride flipped.

Four adults, two men and two women aged between 32 and their early 40s, died on one of the Gold Coast theme park's most recognisable rides, the Thunder River Rapids, just after 2pm on Monday.

They are believed to be members of the same family, possibly visiting the theme park mecca on holiday.

Lia Capes told the ABC she was just about to go on the ride when she saw people running out crying.

"I was speaking to one of the guys and he said it was the raft or the boat thing in front of him, the whole thing flipped and everyone was screaming."

Capes told ABC Gold Coast Dreamworld staff quickly evacuated the area and the park was shut down.

"The little girl that was crying, they asked us to take her because we distracted her, she was bawling her eyes out," Capes told the ABC.

"[Then] people that worked here took her and her little sister away."

Channel 7 reported witnesses watched in horror as two of the victims were thrown from the raft, and the other two were caught inside the ride.

One witness said their sister and niece were on the ride and were "traumatised".

"There is a woman hanging by her foot crushed from the ride," the witness said.

A man who witnessed the incident said the ride flipped at the end of its circuit.

He said a girl was pulled from the ride just before it flipped.

A witness told Sky News that they saw "people hysterically crying, running around... One of the daughters said it was her family".

"We saw this daughter crying, we think it was her mum that owns incvoled in the accident, but not 100 per cent sure," the woman said.

"There was just police and lifeguards everywhere.

"I spoke to a guy and he said he looked behind and the whole thing flipped over."

The woman told the broadcaster that there was believed to be up to six people on the floating raft when it flipped.

The rafts operate on a water-based conveyor belt and was nearing the end of its circuit when the tragedy occurred.

"We just saw people hysterically crying and running around," the woman said.

"We're not 100 per cent sure what happened.

"Maybe one or two people didn't get off or something and yeah, one of the daughters said it was her family."

Another woman told Sky that it was believed there were six members of the same family on the raft.

"They were walking out and they heard the mother, the father, and the uncle all got seriously injured, possibly even died, and the daughter was the only one that survived," she said.

The Thunder River Rapids Ride. Photo / Supplied

Visitors said there had been problems on the ride earlier in the day and engineers were called in, the Nine Network reported.

Police declined to comment on any earlier malfunction at a press conference this afternoon afternoon.

"We were waiting there for about half an hour and engineers had to come," a woman told the broadcaster of the earlier incident.

"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."

Other witnesses, who declined to be named said it was an horrific incident.

"My sister and niece were on the ride, they are so traumatised," one person told the Gold Coast Bulletin.

A man who witnessed the incident told the newspaper the raft flipped at the end of its circuit.

The man, who also declined to be named, said a girl was pulled from the ride just before it flipped.

Park visitors poured out of Dreamworld's front gates after the park was closed about 3.30pm.

Dreamworld said the park is currently closed until further notice.