An Australia chopper crash at the Great Barrier Reef killed two elderly American tourists, despite onlookers' desperate attempts to revive the pair.
The 79-year-old man and 65-year-old women died when the chopper went down near a pontoon on the reef off popular tourist hotspot Airlie Beach late Wednesday. Two other passengers, also from the United States, and the pilot survived with minor injuries.
"As a result of that crash, emergency services have attended and an independent, transparent and robust investigation is currently underway," local police inspector Ian Haughton said.
There was no indication of what caused the crash but Haughton said the probe would look at the mechanical servicing of the helicopter, what happened at the scene that may have been a contributing factor, and any possibility of error.
Witnesses on a nearby dive platform helped drag the passengers from the water, the Brisbane Courier Mail reported, performing resuscitation under phone instruction from emergency services who were an hour away from the remote site in Queensland's Whitsunday region.
But the two Americans could not be saved.
"It's just gut-wrenching. It's not good. My deepest sympathies goes out to those who lost their lives and those that were injured," Whitsunday Mayor Andrew Willcox told broadcaster ABC.
"I know most of the tourism operators in the Whitsundays personally and I know they all hold their passenger experience and safety as their number one priority, so it will be a sombre day for us in the Whitsundays."
The company that operated the helicopter, reportedly Whitsunday Air Services, has suspended operations.