The Arson Squad is investigating the cause of a house fire in Orelia.
The blaze broke out around midday on Monday at the home on Nathaniel Way.
The fire caused extensive damage to the property leaving a bill of $250,000.
It is understood a family of seven lived at the home, including a woman, her son and daughter, four grandchildren and a foster child.
Detectives are asking any motorists who were driving along Christmas Avenue and Nathaniel Way in Orelia between 12pm and 12.30pm on Monday, who have dash-cam vision to come forward.
Anyone with any information relating to this fire is asked to call Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au.
Rewards of up to $50,000 are available for information that leads to the apprehension and subsequent conviction of an arsonist.

New murals to transform Coodanup, Madora Bay public spaces during Mandurah Arts Festival
Teen driver allegedly three times over legal alcohol limit in Rockingham
New councillors elected in Rockingham, Mandurah
Rockingham's Stan Twight Reserve named 2026 WA Football Facility of the Year Award
Homeless campers on Memorial Drive given 24 hours to vacate
Women injured in serious North Dandalup crash
Daughter of man allegedly stabbed to death in East Rockingham pays tribute to father
Peel Thunder claim fourth WAFL premiership
Man dies after suspected stabbing in East Rockingham