Dreamworld is used to seeing people flood through its gates - but never for reasons like this.
Two women - 42-year-old Cindy Low and 32-year-old Kate Goodchild - died in the accident when a raft they were riding in on the Thunder River Rapids ride flipped backwards along with Ms Goodchild's brother Luke Dorsett, 35, and his partner Roozbeh Araghi, 38.
Ms Low's 10-year-old son and Ms Goodchild's 12-year-old daughter were in the raft but survived the incident.
Now as investigators piece together just how four people were killed at the theme park, mourners have begun paying their respects.
A woman lays flowers outside dreamworld (Newshub.)
The entrance to Dreamworld has become a make-shift memorial, and a candle light vigil was held on Wednesday night to remember the four people killed on the ride.
Dreamworld says the park will reopen on Friday for a memorial day, with entry proceeds going to the Australian Red Cross.
Meanwhile, 30 investigators are now trying to piece together how this place of fun turned into unimaginable terror.