Ardent Leisure Group will keep its Dreamworld theme park closed on Wednesday in a mark of respect for four people killed in an accident on a ride.
The theme park operator confirmed the four fatalities in a statement to the ASX on Tuesday evening.
"Dreamworld is working as quickly as possible to establish the facts around the incident and is working closely with the police, emergency services and authorities to do this," the statement said.
The park would remain closed on Wednesday "as a mark of respect for the victims and their families", the company said.
Two men and two women died on Tuesday afternoon when a raft flipped on the Thunder River Rapids ride.
Queensland Ambulance senior operating officer Gavin Fuller said all four suffered fatal injuries and could not be revived by crews at the scene.
Mr Fuller said the ride suffered a malfunction which caused the accident.
Ardent Leisure shares dropped sharply on the ASX when news of the accident emerged around 1545 AEDT.
The stock dropped 20 cents, or 7.8 per cent, in the last 10 minutes of trading to close at $2.35.
