A fire at a derelict house in Mandurah is believed to have been deliberately lit.
Firefighters were called to the house on Stewart Street near Beam Road around 7am on Wednesday.
The house was engulfed in flames.
It took fire crews just over an hour to extinguish the blaze.
The cause is believed to be suspicious.
It's understood the house is often used by squatters.
The Arson Squad are on their way to the scene.
Anyone with information should contact Crime Stoppers on 1800 333 000.
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