By Stuart Condie
SYDNEY–Australia’s second-largest mobile network, Singapore Telecommunications-owned Optus, has been hit by an outage potentially impacting more than 10 million customers, including hospitals and Melbourne’s rail system.
Optus on Wednesday said engineers were investigating a network fault, but didn’t disclose the cause. Customers began reporting problems with their Optus services shortly before dawn on Australia’s east coast.
The outage is the second major incident at Optus in 14 months. In September 2022, a cyber attack resulted in the exposure of more than 10,000 customers’ personal information and led to a class action alleging the company’s failure to protect its customers’ details.
Australia’s federal government has asked Optus for information about the outage and when they expect to restore services, Minister for Communications Michelle Rowland said.
“Connectivity is essential for Australian consumers and businesses. The impacts of this outage are concerning and has left many Australians feeling anxious,” Rowland wrote on X, the platform formerly known as Twitter.
Australia’s largest private-hospital operator, Ramsay Health Care, was among the businesses hit by the outage. Ramsay, which operates more than 70 hospitals, clinics and surgical centers across the country, used its Facebook accounts to direct patient inquiries to its hospitals’ websites.
Trains across Melbourne, Australia’s secondmost populous city, experienced major delays, the service operator said. Victoria state’s transport department said that its call center remained offline due to the outage.
Optus had 10.4 million mobile customers at March 31, according to Singtel’s most recent annual report. ASX-listed Telstra has more than 22 million mobile subscribers and TPG Telecom about 5.3 million.
Write to Stuart Condie at stuart.condie@wsj.com