Police in Queensland, Australia, are investigating a horrific accident that left four people dead on a ride at a popular Gold Coast theme park. Two men and two women in their 30s and 40s died on the Thunder River Rapids ride at the Dreamworld park on Tuesday, with two people thrown from the ride and two others trapped in a conveyor belt underneath after what police describe as a "malfunction," the Sydney Morning Herald reports. The ride—described by visitors as one of the tamest of the park's 50 or so attractions—features six-person circular rafts moving along an artificial river, the BBC reports. The water was drained during a desperate attempt to rescue the two trapped people, reports the Guardian.
Police have yet to name the victims, who are believed to have been part of a family group. "We saw a bunch of people running out hysteric, we saw a little girl screaming for her mum, it was scary," a woman who was lining up for the ride at the time of the accident told reporters. "We believe she was on the ride, I don't believe she was in the same raft, but we do understand from what she said it was her family involved and she was screaming for her mother." Queensland Premier Annastacia Palaszczuk has promised there will be a full investigation of the "horrific, horrific scene." The theme park, which is Australia's biggest, says it will be closed until further notice. (More Australia stories.)