Arson Squad Detectives have charged a 42-year-old man in relation to a fire in Pinjarra this morning.
Emergency services were called to the fire on Uldina Place around 5.35am on Thursday.
All the occupants were safely evacuated, but the unit was entirely destroyed.
Police arrested a 42-year-old man at the scene.
He has since been charged with breach of duty of a person in control of an ignition source or fire.
He is due to appear in Mandurah Magistrates Court tomorrow.
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