Wild winds in the city of Melbourne and across the Australian state of Victoria have torn off roofs, downed trees and left more than 450,000 homes without power.
Energy manager AEMO said the damage was severe and warned that some customers would not have electricity over the weekend or even by early next week.
The storms came at an awkward time as many people in Melbourne were preparing to travel elsewhere in the state.
The weekend marks the first time in months that people will be able to move freely around Victoria after coronavirus restrictions were lifted.
The Victoria State Emergency Service said it received more than 2,500 calls for help, with about 300 people reporting damage to their properties.
One of the hardest hit areas was Red Hill, a tourist spot south of Melbourne.
Residents reported trees being ripped out of the ground and debris everywhere.
Internet services also went offline for about 125,000 households, affecting thousands of people who are still working from home.
Some train services were suspended and several vaccination centres were closed due to the weather. Businesses were also hit by power outages.
Bureau of Meteorology senior forecaster Christie Johnson said several places recorded their strongest wind gusts in a decade or more, including Ben Nevis mountain where winds hit 73mph.
In Bass Strait, between Victoria and Tasmania, gusts hit 103mph.
Ms Johnson said the winds were caused by an intense low-pressure system moving across the state and are expected to ease on Friday evening.
The storm also caused damage in the city of Adelaide, leaving 30,000 homes and businesses without power.