Four people have died, including a young boy and baby, after two separate crashes on south-east Queensland roads on Sunday.
Three of the fatalities came from a crash involving a truck and a car on the Bruce Highway at Gunalda, south of Maryborough, about 11.30am.
The 45-year-old male driver of the car and a nine-year-old boy, who was a passenger, were declared dead at the scene. A one-year-old girl, also a passenger in the car, was airlifted to the Lady Cilento Children's Hospital in a critical condition, but died in the evening.
The car caught fire following the crash and forced the closure of the highway in both directions, with the road remaining closed until just after 7pm. Police set up a diversion between Gympie and Maryborough through Tin Can Bay and Maryborough-Cooloola roads.
Meanwhile, the driver of a car involved in a collision with a bus at Bilinga on the Gold Coast also died on Sunday.
The crash happened about 11.20am on Golden Four Drive, with the 35-year-old man being declared dead at the scene, while the bus driver and two others were taken to hospital for treatment of minor injuries and checks.
The road was closed while police investigated the incident, but reopened about 4.30pm.
The Forensic Crash Unit was investigating both incidents.