Western Power says it has started gradually adding customers to the backup generation service as it investigates a fault which has left about 16,000 homes and businesses in the Goldfields without power on Thursday.

Power was lost in several towns including Kalgoorlie-Boulder, Kambalda, Coolgardie, and Southern Cross just after 9.30am because of an unknown fault along the 220kV line which feeds the Goldfields region.

A Western Power spokesperson said the cause was being investigated and once identified, crews would work “swifty and safely” to repair the fault and restore power.

“However, we have commenced the process to start the backup generation service at West Kalgoorlie Terminal to support the townsite in the event the fault requires extensive patrols or complex repairs,” the spokesperson said.

“This process can take a number of hours as we gradually and safely add customers in sections.

“We thank the community for their understanding as we work to resolve the fault.”

The City of Kalgoorlie-Boulder has confirmed several facilities have been closed as a result of the outage, including the William Grundt Memorial Library and the Goldfields Oasis.

Western Power’s outage map at 11am was showing power had already been restored to several customers across Kalgoorlie-Boulder.