A mid-air collision between two helicopters Australia killed four people and left three others in critical condition, authorities said on Monday.
The collision happened around 2pm local time near the popular tourist strip of Main Beach on the Gold Coast south of Brisbane.
“These two planes went down in a collision on the sandbar just outside Sea World Resort,” Queensland Police Inspector Gary Worrell, a regional duty officer for the south-east region, told reporters.
He added that it was difficult for rescue services to get onto the sandbar, which is not far from shore.
There were thirteen people in the two helicopters, according to Queensland Ambulance Service (QAS) Jayney Shearman. Four people died, three suffered serious injuries and six suffered minor injuries, including lacerations from broken glass.
All of the injured were taken to the hospital, she said.
Photos from the site show debris lying on a strip of sand, with personnel gathered ashore and numerous vessels in the surrounding waters.
Worrell said while it is still too early to determine the exact cause of the accident, initial investigations indicate that one helicopter had taken off and the other was landing when they collided.
One helicopter “had its windshield removed and landed safely on the island. The other (helicopter) crashed and was upside down,” he said.
He added that after the crash, nearby police officers and members of the public rushed to the site and tried to remove the people in the helicopter and give them first aid.
Australian Transport Safety Bureau (ATSB) chief commissioner Angus Mitchell said in a statement that an investigation into the collision had been launched.
Investigators from the ATSB offices in Brisbane and Canberra are being deployed to the scene to collect evidence, examine the debris and map the location, and interview witnesses and those involved, Mitchell added.
He asked people who witnessed the collision or who saw helicopters in flight to contact investigators. A preliminary report will be available in the next six to eight weeks, with a final report after the investigation is complete, he said.
In a statement released on Twitter, Queensland Prime Minister Annastacia Palaszczuk expressed her “deepest condolences” to the families of the victims and everyone affected. “What happened today on the Gold Coast is an unimaginable tragedy,” she said.
Police say Sea World Drive has been closed to traffic and are urging motorists and pedestrians to avoid the area.
Sea World Drive is the main access point for the tourist-popular marine park in the heart of the Gold Coast. The region is currently in peak tourist season and schools are closed for the long summer break.
CNN has reached out to Sea World for comment.