ARSON squad detectives are looking for information about a house fire in Coolbellup on Sunday.
Occupants of the house were woken by an explosion and saw a gazebo in their backyard on fire.
Emergency services went to a home on Dion Place at 3.29am, but the gazebo and contents were destroyed.
The estimated damage is up to $45,000.
The cause of the fire is believed to be deliberate and investigators would like to speak to anyone who witnessed any suspicious activity, people or vehicles about the time of the fire or earlier in the evening.
Call Crime Stoppers 1800 333 000.