Four people were killed at a theme park in the state of Queensland in Australia after a malfunction in one of the rides, CNN reported. Police officials said the incident at the Dreamworld theme park – the country’s biggest – at the City of Gold Coast took place at around 2.20 pm local time.

The officials said the malfunction on a river rapids ride led to two of the victims being ejected, and the other two being pinned by the ride’s conveyor belt system. Senior Queensland Ambulance Service official Gavin Fuller said the four “sustained injuries which were incompatible with living”. Queensland Police inspector Todd Reid said a crime scene had been established at the park, with investigators working with park officials to determine the cause of the malfunction, according to Reuters.

Dreamworld Chief Executive Officer Craig Davidson said the theme park had been closed after the incident. “We are deeply shocked and saddened by this and our hearts and thoughts go to the families involved and to their loved ones,” he said. Australian Prime Minister Malcolm Turnbull said he was “very saddened” by the “tragic accident”.