Four people were killed in a mid-air collision between two helicopters near SeaWorld on Australia’s Gold Coast.
Nine other passengers on both planes were treated for injuries, Queensland Ambulance Service said.
Three passengers – a woman and two young boys – have been taken to hospital in critical condition.
The Australian Transport Safety Bureau (ATSB) has said it will investigate.
The collision happened at around 14:00 local time (04:00 GMT) along the tourist strip known as Main Beach, about 75 km (47 mi) south of Brisbane.
Queensland Police Gary Worrell told reporters that one helicopter was taking off while the other was landing.
He said that four deaths and three serious injuries have occurred in the same plane.
He said that this is a difficult scenario. “The area it’s located in, on the sandbank, it was difficult to access, it was difficult to get our emergency services to the scene to manage it properly.”
Pictures taken from the crash site show debris strewn around the area and a damaged helicopter apparently lying upside down in front of SeaWorld Resort.
The other helicopter has the iconic Marine Park logo on its side and appears to have landed safely after the collision.
Sea World Drive, the main access road to the Marine Park, has been closed to traffic by local police.
He urged motorists and pedestrians to avoid the area as first responders examine the scene.
Investigators from ATSB offices in Brisbane and Canberra are being deployed to the scene to collect evidence, examine the wreckage and interview witnesses.
ATSB Chief Commissioner Angus Mitchell has also asked witnesses who saw the collision or the helicopters in flight to contact investigators.
He added that a preliminary report would be released in the next six to eight weeks, with a final report after the investigation is completed.
The Gold Coast region is currently at its peak tourist season with children on summer holidays.
