Major Crash officers are investigating a fatal crash that occurred in Waroona on Friday, December 21 at around 9:40pm.
A black 1999 model Holden Commodore wagon was travelling north on South Western Highway, approaching Tallathalla Road when it left the carriageway and struck a tree.
The driver has been identified as a 28-year-old man, who died at the scene as a result of injuries sustained during the crash.
Three other passengers were injured and received medical treatment.
Major Crash investigators would like to speak with two motorcycle riders who were travelling together, in a southerly direction along the South Western Highway between Pinjarra and Waroona around 9.30pm and who may have seen the crash.
Investigators are asking the riders to come forward.
Anyone who saw the crash or the Holden Commodore prior to the crash, or can identify the two motorcycle riders, is asked to call Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au