Two men and two women have been killed on the Thunder River Rapids ride at Dreamworld on the Gold Coast.

Two of the four victims were thrown off the ride when it malfunctioned and the other two were trapped inside.

Those killed include two men, aged 35 and 38, and two women, aged 42 and 32. They were reportedly relatives visiting from Canberra, according to Nine News.

Dreamworld | Thunder River Rapids 4
Dreamworld | Thunder River Rapids 4

Queensland Ambulance acting supervisor Gavin Fuller said ‘some sort of malfunction’ occurred, causing two people to be thrown from the raft and two others to be trapped on the conveyor belt.

He could not say whether the two people trapped were underwater, and would not elaborate on any of the injuries the four people sustained.

‘They sustained injuries incompatible with life,’ he said.

Dreamworld staff drained water from the ride in an attempt to save the trapped passengers and treated those injured before paramedics arrived.

“[The ride] had sustained some sort of malfunction causing two people to be ejected … another two people were caught inside the ride,” Queensland Ambulance Service senior operations supervisor Gavin Fuller said.

Dreamworld chief executive Craig Davidson said: “We are deeply shocked and saddened by this and our hearts and our thoughts go to the families involved and their loved ones.”

“Two males and two females, they were assessed by Queensland ambulance personnel and had all sustained injuries that were incompatible with living.”

According to the Queensland Ambulance Service (QAS), injuries that are incompatible with living are those “where it would be appropriate to withhold the commencement of CPR”.

Mr Fuller said the QAS had multiple units at the scene, including critical care paramedics, who arrived at Dreamworld to find park staff trying to render first aid.

“A number of the staff that were here today from Queensland ambulance have been deeply affected by this terrible accident that’s occurred today,” he said.

Dreamworld | Thunder River Rapids 2
Dreamworld | Thunder River Rapids 2

Dreamworld chief executive Craig Davidson said the accident happened at 2:20pm (AEST).

“At this stage, the park is closed and Dreamworld is working closely with police and emergency services and authorities to establish the facts around the incident,” he said.

Mr Davidson said the company was “deeply shocked and saddened by this and our hearts and our thoughts go to the families involved and to their loved ones”.

‘Earlier in the day it had broken down,’ Lisa told Sydney Morning Herald.

‘It had broken down and we went back a couple of times to this particular ride.

‘We were standing on the bridge watching and the water had stopped.

‘There was no rapids.’

They said the accident happened 10 minutes after they left the scene, the Sydney Morning Herald reported.

Another woman told Nine News engineers were called to the ride earlier in the day.

‘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 woman said.

They said the accident happened 10 minutes after they left the scene, the Sydney Morning Herald reported.

Dreamworld | Thunder River Rapids 3
Dreamworld | Thunder River Rapids 3

Our condolences go out to all those effected by today’s events. Theme Parks are meant to be a place of fun and enjoyment, not tragedy.