The crash which occurred in Carlotta, 20km south of Nannup, on Monday 22 October 2018.
Around 3:45am a white Toyota Prado was driving south on Vasse Highway when it drifted into the north bound lane and onto the gravel verge.
The 57 year old male driver lost control and rolled onto Vasse Highway.
The driver and a 54 year old female passenger received minor injuries as a result of the incident. An 89 year old female passenger received serious injuries and was conveyed to Bunbury Regional Hospital.
Anyone with information regarding this crash or who saw the white Prado before the crash is asked to contact Crime Stoppers on 1800 333 000 or report the information online at www.crimestopperswa.com.au