There are traffic delays and the right lane northbound blocked with emergency services on site.
Traffic has slowed on Forrest Highway with the northbound right lane blocked just south of Myalup after a truck rolled.
Four Department of Fire and Emergency Service crews were called to the scene at around 5.20am on Wednesday.
They remain on scene as they attempt to remove the truck, while traffic has slowed.
There are reports of minor injuries.
Meanwhile a man in his 60s has died following a truck rollover on South Coast Highway at Kalgan near Albany.
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