Police are looking at fatigue as the possible cause of a single-vehicle crash that put two adults, a teen and a girl in hospital.

Goondiwindi Senior Sergeant Richard McIntosh said the initial investigation indicated that the driver lost control of their vehicle, veered off the Leichhardt Highway about 2am, before over correcting and flipping their car.

"We're looking at fatigue, but there could be a number of causes," he said.

A girl in her early teens suffered serious leg and pelvic injuries, while a young girl also sustained serious injuries.

A woman, aged in her 30s, sustained serious shoulder, chest and leg injuries.

A fourth person had minor injuries.

Paramedics transported all four to the Goondiwindi Hospital where they were transferred to rescue choppers.

The woman was flown to the Princess Alexandra Hospital while the teen and the girl went to the Queensland Children's Hospital.

The police investigation continues.


Originally published as Fatigue possible cause of crash that put teen, child in hospital