Police, St John WA ambulances, and firefighters remain at the scene. Police, St John WA ambulances, and firefighters remain at the scene. Credit: Simon Santi / The West AustralianMotorists have been warned to avoid a section of Mitchell Freeway after a fatal crash on Wednesday night. Police, St John WA ambulances, and firefighters remain at the scene. Main Roads WA warned motorists there was congestion and to exercise extreme caution.