A FOUR-YEAR-OLD boy and a 50-year-old woman have died after the vehicle they were travelling in left the Bruce Hwy, flipped onto its roof and landed in Greta Creek 35km north of Proserpine.
It's believed the woman died at the scene of the accident and paramedics fought to save the life of the boy after the single-vehicle crash, but he later died at Proserpine Base Hospital.
Police were called to the accident at 7.20am yesterday.
There were four occupants travelling in the small sedan.
A Mackay Health Service spokeswoman said a 40-year-old male and a 19 year-old girl, who were also in the vehicle, were currently recovering at the Proserpine Base Hospital.
"The girl only received minor injuries and the man is currently in a stable condition," the spokeswoman said.
Swift water rescue crews from both the Bowen and Proserpine Queensland Fire and Rescue crews were called to assist with the accident.
A Queensland Fire and Rescue spokeswoman said three swift water rescue technicians from Bowen attended the scene.
"Swift water technicians were dispatched and helped with one entrapped person," she said yesterday.
She said Queensland Ambulance Service crews had administered CPR to the boy.
"The 40-year-old male patient had suffered chest injuries," she said.
"After the incident he was conscious and talking and able to walk before he was transported to hospital."
A Mackay Police spokesman said it was believed the four occupants were related to each other.
"It's believed they may have come from the central north Queensland area," he said.
The spokesman said he didn't believe the fatal accident caused the Bruce Hwy to close at any time.