A 74-year-old Karrinyup man returned from a shopping trip this morning to discover his home on fire.
Fire crews from Daglish, Osborne Park and Duncraig were called to the Davenport Street duplex after smoke was seen coming from the roof about 10.10am.
Lawrence Bartlett had gone on a walk to the nearby shopping centre shortly before.
The fire started in the roof space.
When Mr Bartlett returned firefighters were battling the blaze and trying to confine it to the roof.
Part of the roof has collapsed inside the home while parts of the duplex are now smoke and water affected.
Mr Bartlett is due to go on holiday at the end of the week but is unsure if he will be able to return to his home before he leaves.
The cause of the fire is understood to be electrical.