Mr Viral
A recent failure within the Optus network led to an outage of the Triple Zero (000) emergency service. Calls to the number are made for the most serious of medical conditions and unfortunately this outage means a number of critical calls did not reach their destination.
Tragically this has been correlated to the deaths of at least four people.
This event, which unfolded over a period which we understand lasted up to 12 hours, resulting in widespread public outrage, intense government scrutiny, and a renewed focus on the resilience of our telecommunication services.
The outage, which began in the early hours of Thursday, September 18, 2025, was initially downplayed by Optus, who reported a two-hour disruption impacting just a handful of customers.
However, early investigations have indicated a far longer and more impactful outage occurred.
The Cause: A Botched Network Upgrade
The root cause of the crisis was identified as a botched network upgrade.
Specifically, a firewall update has been identified as the cause of the outage at Optus. We now know that established processes were not followed.
There is currently an immediate halt to all further changes in the Optus network system until they can introduce greater monitoring, testing and compliance and reviews of change processes.
Network infrastructure needs to be updated periodically and when that infrastructure is responsible for routing critical calls, like those to triple zero, you would expect significant planning to be done prior to the update. This will be the focus of investigation(s).
Whenever a task like a firewall replacement is entertained, a rollback strategy should be in place, in the event the playbook doesn’t pan out as expected. The project team will have had approval to commence the upgrade, what happened next is currently unknown.
It is likely the team hit issues and call traffic didn’t route as expected. With weeks and maybe months of planning leading up to the event, there would be a temptation to proceed and work through any issues to get it done during this outage, but at some point you need to admit defeat, rollback and try again later when issues are understood and resolved.
It is unclear Optus was even aware there was an issue until much later into the time frame, with the latest information today suggesting that people called Optus to let them know they couldn’t get through to 000 and an offshore call center who failed to relay issues with the emergency number. There’s a suggestion that staff at this international call center were unfamiliar with what 000 was.
It’s not unusual to have calls redirected to a 3rd party during an upgrade, but it seems in this case, the calls simply wouldn’t go through.
Any suggestion that calls to 000 should have been immediately escalated, given the seriousness involved. There are reports that as many as 600 calls went unanswered.
This may be one of the critical issues and something that should be immediately addressed at Optus and validated at other telcos to ensure this never happens again.
The impact of the outage was most severe consequences were concentrated in South Australia and Western Australia. SA Premier, Peter Malinauskas suggests Ambulance SA were the ones who flagged the issue with the State Government, not Optus.
Over the course of the outage, hundreds of calls to Triple Zero from Optus customers failed to connect.
When I think about what I would do if I was with someone requiring urgent medical assistance, I’d call 000 and when I couldn’t get through, I’d try a couple more times before realising I need a plan B.
Depending on the circumstance, it may be practical to throw them in a car and drive them to a hospital, but other times an ambulance (road or air) would be the only option. At that point I’d like to imagine I’d call the hospital, or ambulance directly, but these are intense situations and your normal rational brain may be unavailable during peak stress, particularly when it involves a life or death situation with a loved one.
The response from both federal and state governments was one of outrage and a commitment to a thorough investigation. The Australian Communications and Media Authority (ACMA), the national telecommunications regulator, immediately launched a formal investigation into the incident. The federal government has also flagged the potential for significant penalties for Optus over the failure.
This was not the first time Optus had experienced a major outage with serious consequences. In November 2023, a nationwide Optus outage disrupted services for over 10 million customers and also impacted the ability of some to call Triple Zero.
That event led to a government review and recommendations aimed at preventing a recurrence. The September 2025 tragedy has raised serious questions about whether the lessons from the previous outage were adequately learned and implemented.
As with the investigation of Optus’ massive data breach back in September 2022, the results should be made public for the whole industry to learn from.
The initial press release from Optus came after a public press conference that disclosed the issue. Governments have flagged their disappointment with this being done prior to a report and disclosure to them. The press release can be found here – https://www.optus.com.au/about/media-centre/media-releases/2025/09/optus-launches-investigation-into-triple-zero-call-failures
What has happened is completely unacceptable. We have let you down. – Optus CEO Stephen Rue
Optus has an updated statement on their website regarding the incident from CEO Stephen Rue –https://www.optus.com.au/about/media-centre/media-releases/2025/09/21-september-2025-ceo-stephen-rue-update
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