The West Australian city of Perth has been declared a natural disaster zone, after storms ripped across the city and several regional towns on Monday.
Emergency services received up to 2000 calls for help, as winds gusted up to 120 km/h and hail stones the size of golf balls battered the area. Homes were damaged and streets flooded.
Premier Colin Barnett expects the damage bill to top $A100 million.
Lightning knocked out a substation, causing widespread blackouts that affected 150,000 homes and businesses throughout the west Australian city, the ABC reports.
Twenty people had to be evacuated from the emergency department at a hospital in the city's northern suburbs after parts of the ceiling caved in.
One hundred residents were also removed from an apartment threatened by a landslide.
The storm ended one of Perth's longest recorded dry spells.