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.
Mandurah Crab Fest boasts huge range of free, family friendly entertainment
Fuel prices surge in Perth, Mandurah
Teen boys charged over Mandurah burglaries
Tragic update in search for missing man Robert Snyder
Premier Roger Cook to leave Kwinana electorate, move to Perth
Mandurah Marine Rescue's new vessel named in memory of nun who survived 1959 boating accident
Teen dies in motorbike crash at Waroona Dam
Shark alert issued after whale carcass reported at Preston Beach
Kwinana businesses to refuse serving students during school hours