South West Traffic officers are trying to figure out what happened in the moments leading up to a truck and pedestrian colliding yesterday.
A 23-year-old Donnybrook man remains in Royal Perth Hospital this morning with serious head and back injuries after being airlifted by the RAC helicopter from the scene of a crash in the south west yesterday.
Around 7.30am yesterday an Isuzu truck was travelling north on South Western Highway just south of Boyanup when it collided with the 23-year-old victim.
The man was walking north along the side of the highway next to the northbound lanes.
Following the incident the truck driver stopped at the scene and emergency services were called to attend.
Police and St John's Ambulance crews attended before the man was airlifted to Royal Perth Hospital.
Anyone with information regarding this crash, or who saw the pedestrian or Isuzu truck prior to the crash, is asked to call Crime Stoppers on 8900 333 000 or report the information online at www.crimestoppers.wa.gov.au.