BRISBANE, AUSTRALIA — Four people were killed in a horrific accident at Dreamworld, a theme park on the northern end of the Gold Coast in Queensland, Australia on Tuesday.

According to the News.com.au, the victims have been identified as Kate Goodchild, her brother Luke Dorsett, his partner Roozi Araghi and a 42-year-old woman. The victims were on the Thunder River Rapids ride, which was described on the park’s website as a “moderate thrill,” or family-friendly attraction.

The Gold Coast Bulletin reported that the victims’ raft hit an empty raft that was stuck at the final stop of the ride and flipped. Two of the victims were flung out of the raft into the water, while two others were trapped under the raft.

Police are reviewing the CCTV footage for clues as to what caused the malfunction.