The forensic crash unit is investigating a fatal traffic crash in Dysart (Mackay) this morning, 27 September.
Emergency services were called to Golden Mile Road at 9.05am after a single vehicle left the road and rolled.
A one-year-old girl was declared deceased at the scene.
A five-month-old boy has also sustained serious injuries.
The driver of the vehicle, a 22-year-old Moranbah woman, sustained minor injuries.
Police are appealing to anyone with information, including dashcam or CCTV footage, to come forward.
If you have information for police, contact Policelink by providing information using the online suspicious activity form 24hrs per day at www.police.qld.gov.au/reporting.
Report crime information anonymously via Crime Stoppers. Call 1800 333 000 or report online at www.crimestoppersqld.com.au or call 131 444.
