A 35-year-old man has been charged with the alleged murder of his partner at their Warnbro home.
It is alleged the man assaulted mother-of-four Erica Hay at the property on Currie Street sometime between 7.30am on Thursday and 1am on Friday.
He then allegedly set the house on fire while Ms Hay was still inside.
Her body was later discovered by emergency services.
The accused allegedly fled the burning home with Ms Hay's three-year-old daughter who was taken to Rockingham Hospital with smoke inhalation.
The 35-year-old South Kalgoorlie man has been charged with one count of murder and one count of criminal damage by fire.
He is due to appear in the Perth Magistrates Court today.