Major Crash Investigators are seeking information regarding a fatal crash in Birchmont last month.
Around 7.20am on Friday October 27, a blue Mazda sedan and a Kenworth truck were involved in a collision while driving south on Forrest Highway.
The 68-year-old female driver of the Mazda and her 69-year-old male passenger were taken to Royal Perth Hospital.
The female driver died on Thursday, November 9.
The driver of the truck wasn't injured.
Police urge anyone who saw the crash, has dash cam footage, or saw the vehicles involved travelling in the area prior to the crash, to contact Crime Stoppers on 1800 333 000.
Early voting for Secret Harbour by-election begins Monday
Welfare concerns for missing Swedish national last seen in Warnbro
Wanted man last seen in Golden Bay
Passenger critically injured in West Pinjarra crash
Unregistered painter fined for requesting hefty deposit from Singleton homeowner and not doing the job
Police hunt driver following dangerous Baldivis pursuit
Welfare concerns for boy last seen at Port Kennedy skate park
Rubbish truck catches fire in Baldivis
Driver injured in bus crash in Rockingham