Million of Australians They were left without a phone or internet connection on Wednesday after the country’s second-largest telecommunications provider suffered an unexplained nationwide outage.

The outage paralyzed payment systems and online operations and created chaos in the morning rush hours as train networks and ride-sharing services were briefly disrupted in some cities.

Optus CEO Kelly Baer-Rosmarin ruled out a cyberattack, but in an interview with ABC Radio did not give a reason for the outage, which has already entered its sixth hour, or say how long it would take to restore services.

“It’s very unlikely (that the issue started within software in Optus’ networks), our systems are actually very stable… and that’s very rare,” she said.

“We are working hard to get it up and running as soon as possible.”

Optus is the Australian unit of telecommunications company Singapore Telecommunication and has more than 10 million customers, about 40% of Australia’s population.

“Without my phone I can’t do almost anything. I’m looking for a bank, and when you can’t use your phone and Google pretty much, you’re lost,” Angela Icahn said outside an Optus store in Sydney’s central business district.

Construction worker Kyle, who did not give his full name, said he wanted answers from Optus.

“I was late for work and couldn’t tell my boss about it. When I got to the site I couldn’t find my boss, it was a big day,” he told Reuters.

An Optus spokesperson told Reuters in a statement that the company “deeply apologizes to customers.”

Commonwealth Bank, the country’s largest bank, said in a statement that some customers may experience difficulties with some of its services.

Federal Communications Minister Michele Rolland said she had “limited” information about the outage.

What we do know is that this is deeply wrong. It happened deep inside the network. “It has widespread ramifications across mobile, fixed and broadband services for Optus customers,” Rowland told reporters.

Media reported that Melbourne’s train networks were forced to stop operating for approximately 30 minutes due to the outage, leading to delays during the morning peak period.

“Significant delays continue on all lines with selected modifications and cancellations,” the city’s subway service said on the X website.

Hospitals and emergency services across the country were also affected by power outages.

Ramsay Health Care, which has 70 hospitals and clinics in Australia, has had its phone services affected.

“At this time, we do not know how long this outage will last. If you need to contact your local Ramsay Hospital, please direct inquiries via the contact form on your local hospital website.

Triple zero (“000”) emergency calls were not working from Optus landlines.

“We encourage any customer who needs to contact emergency services to use the mobile phone line to call 000,” Optus said in a statement.