A serious crash in West Pinjarra has left a passenger fighting for life after two cars collided and a four-wheel drive rolled.
Major crash officers are investigating the cause of the collision, which happened on Forrest Highway about 6.40pm on Thursday.
A police spokeswoman said a white Mitsubishi Pajero was heading south on Forrest Highway when it hit a white Hyundai i30.
The Hyundai was turning right from Greenlands Road onto Forrest Highway when the cars collided.
Police said the Mitsubishi rolled before first responders located a critically injured passenger.
The passenger — an adult male — was transported to Royal Perth Hospital.
The driver of the Mitsubshi was taken to Peel Health Campus as a precaution and the 25-year-old woman driving the Hyundai was taken to Fiona Stanley Hospital for non-life-threatening injuries.
Anyone who witnessed the crash is urged to contact Crime Stoppers on 1800 333 000 or make a report online here.
Dash-cam or mobile phone footage can be uploaded to investigators here.
