As Optus executives faced the wrath of a Senate inquiry on Monday over its fatal 18 September Triple Zero outage, the company shared a detailed timeline of what it said occurred before, during, and after the incident.
The 14-hour outage has been linked to four deaths and more than 450 failed Triple Zero calls in South Australia, Western Australia, the Northern Territory, and parts of far west New South Wales.
Here are some of the key moments from Optus’s timeline, according to the submission document it shared with the Senate committee.
All times are in Australian Eastern Standard Time.
Monday, 8 September 2025
3.31pm: 'The first point of failure’
Workers from Optus and its networking partner Nokia hold a team meeting to discuss a planned firewall upgrade at Optus’s Regency Park exchange in South Australia.
“Some of the required members of the Optus core network engineering team were not present,” the company admitted in its submission.
Optus CEO Stephen Rue told the Senate committee on Monday that the engineers’ absence in that meeting was “the first point of failure”.
Thursday, 18 September 2025
12.17am: The outage begins
Nokia begins the planned firewall upgrade and initiates a so-called ‘soft lock’ process which prevents new calls from being established through the Regency Park exchange but allows existing ones to continue.
Workers mistakenly do not redirect Triple Zero traffic off the system before applying the soft lock.
The first unsuccessful Triple Zero call takes place just one minute later, at 12.18am.
In the following half an hour, Nokia raises an incident ticket after an engineer notices potential voice call failures, and Optus raises a ticket of its own after an engineer reviews automated emails which show higher call failures which “were not specifically identified as Triple Zero”.
Optus and Nokia engineers discuss the potential issue in a Microsoft Teams chat.
2.10am: The ‘hard lock’ begins
Nokia completes its implementation of a so-called ‘hard lock’, which prevents new Triple Zero calls from being established and ends any which may have been taking place through the Regency Park exchange.
10.13am: Optus customers start flagging Triple Zero issues
Over about three hours, at least five Optus customers contact the company’s call centre team in Manila, Philippines, notifying them of issues calling Triple Zero.
1.15pm: SA Ambulance warns Optus of outage
Optus receives three calls from the South Australian Ambulance Service, notifying it of a potential issue with emergency calls.
An Optus representative responds that the company is not currently aware of any outages, but the issue is escalated and Optus begins internal testing of Triple Zero calls.
1.51pm: Optus declares a major incident
After a Microsoft Teams meeting between Optus and Nokia staff, Optus declares a major incident internally, with a description which partially reads, “Mobile - Optus mobile users in South Australia have reported they are unable to call Triple Zero. 1 – Critical.”
SA Police begin to report issues with Triple Zero calls around the same time.
2.16pm: Optus PR and communications informed
Optus’s director of security and public safety sends a text message to the company’s chief corporate affairs and marketing officer Felicity Ross, stating there is a network issue impacting calls to “Triple Zero in SA & WA since 3am. Network change caused it, now being rolled back”.
In subsequent text message, Ross asks, "Did we only get told about this? How many calls?"
She is told, "...Found out about 30 minutes ago ... unsure of volume of calls yet ... Current advice is 10 failed calls to [Triple Zero] today."
Minutes later, Optus's director of security and public safety advises the vice president of corporate communications and the associate director of government affairs of an outage impacting Triple Zero calls in SA and WA.
2.23pm: Nokia starts rolling back changes
Following a request from Optus to unlock the Regency Park exchange, Nokia begins rolling back the changes it had made.
2.31pm: Optus tries to call government, Nokia unlocks Regency Park
Optus’s associate director for government affairs calls a senior adviser for Communications Minister Anika Wells, but the call is not answered and no message is left.
At the same time, the final unsuccessful Triple Zero call takes place and Nokia unlocks the Regency Park exchange to allow calls through again.
2.34pm: Outage is declared resolved
Optus tests Triple Zero calls again and confirms the issue has been fixed.
The communications minister’s senior adviser calls back and is informed of the issue and told Optus will send an email when it is resolved.
Optus also calls industry regulator ACMA (Australian Communications and Media Authority) to report the issue.
2.45pm: Optus emails the government
Optus sends an email to the Communications Department and the minister’s senior adviser, partly stating, “… Optus has received reports that some customers in SA and WA are experiencing impacts to Triple Zero calls.
“Suspected cause has been indicated to stem from our Regency Park exchange ... have commenced the welfare check processes and relevant protocols.”
2.51pm: Optus CEO notified of outage
Optus CEO Stephen Rue and fellow members of the Optus executive committee are verbally told about the outage, more than 14 hours after it began.
Rue told the Senate committee he was informed at this time that the issue had blocked 10 calls, but had been fixed.
Around the same time, Optus updates the Communications Department again, partly stating, "… Services have returned to normal … protocol reporting shows that 10 calls may have been impacted ... and welfare checks will be made."
3.48pm: Nokia can’t find failed call data
Nokia, which had been asked by Optus to provide details of the failed Triple Zero calls so that welfare checks could be carried out, advises the Regency Park data shows no unsuccessful calls.
“Unsuccessful Triple Zero calls were not captured in the data as the calls did not reach the part of the core network from which the records are usually obtained,” Optus said in its submission.
In the following 15 minutes, Optus’s engineering team figures out a new method for identifying and extracting the failed Triple Zero calls, and begins that process.
7.50pm: Optus finds 100 customers were affected
Analysis of failed Triple Zero calls finds 100 customers were impacted — not 10 as originally thought.
Optus’s chief corporate affairs and marketing officer Felicity Ross is advised of the increase around 15 minutes later.
She would go on to tell the Senate committee she regretted not escalating that information straight away.
“Looking back, and given what I now know — and that it had not been escalated through other parts of the company — I definitely wish I had spoken to the CEO,” she said yesterday.
8.34pm: First welfare checks begin
Almost half an hour after being sent details of the 100 failed calls at around 8.08pm, Optus’s contact centre team begins the first welfare checks.
8.43pm: First deaths are reported
An Optus customer reports the first fatality during a welfare check phone call, before a second death is reported just 15 minutes later.
The welfare check phone calls are completed by 9.33pm.
11.06pm: Contact centre leader informed of fatalities
The community manager of the Optus contact centre is informed of the two reported deaths linked to failed Triple Zero calls.
Optus engineers soon find an additional 524 customers may have been affected, taking the potential total to 624.
Optus says 455 customers could not connect to Triple Zero during the outage. Image: Shutterstock
Friday, 19 September
12.25am: Fatalities reported to senior Optus staff
The community manager of the Optus contact centre emails several Optus vice presidents and a director to update them on the welfare checks and two reported fatalities.
CEO Stephen Rue has since told the Senate committee that this email was not seen by Optus staff until later that Friday morning.
7.45am: Optus executives meet, CEO informed of deaths
Key Optus executives meet “to discuss next steps”, shortly before chief corporate affairs and marketing officer Felicity Ross reaches CEO Stephen Rue by phone and informs him of the two reported fatalities.
8.52am: Optus CEO calls parent company Singtel
Stephen Rue phones Yuen Kuan Moon, CEO of Optus’s Singaporean parent company Singtel Group, to advise him of the key facts.
Rue could not reach Optus Chairman John Arthur by phone, as he was on leave overseas at the time.
9am: Crisis Management Team holds first meeting
Optus’s Crisis Management Team holds an initial meeting in person and on Microsoft Teams, which the CEO dials in to at 9.10am.
Around the same time, Stephen Rue sends a text message to John Arthur informing him of the situation.
An Optus Incident Crisis Communications Team meeting is held at 10am, just as a list of the 524 extra calls for welfare checks are provided to the company’s contact centre team.
10.28am: Optus CEO texts board members
Stephen Rue texts non-executive board directors Michaela Browning, Nicki Tan, and Andrew Parker about the situation over a five-minute period.
Optus’s Crisis Management Executive Committee holds a meeting a short time later.
12.04pm: Second wave of welfare checks begin
Optus’s contact centre begins the 524 additional welfare check calls.
The company is advised of a third fatality during one of the calls.
More crisis meetings are held, and it is agreed the CEO will hold a press conference at 3.10pm following a board meeting at 3pm.
2pm: New welfare checks completed, talking points drafted
Optus’s contact centre finishes the new wave of 524 welfare checks, just before Felicity Ross emails the Optus board with draft talking points related to the outage.
2.18pm: Optus emails Singtel about press conference
Optus emails Singtel to advise of its plan to have Stephen Rue speak to the media at 3.30pm, after regulators and government contacts are briefed.
Rue has an email exchange with Optus directors discussing details of the outage in SA, WA, and NT.
2.36pm: Optus CEO calls ACMA
Stephen Rue phones ACMA Chair Nerida O'Loughlin to advise her of the outage and the reported fatalities.
“This was the first information to the ACMA that the issue was much more serious than indicated in notifications on 18 September, and it was the first time Optus informed the regulator that fatalities had occurred,” the company said.
3pm: Optus holds board meeting
Optus’s board meets for 35 minutes.
“The board was provided an update on the Triple Zero outage impacting SA, WA, NT and known fatalities, as well as the plan to inform key stakeholders and plan to hold a media conference that afternoon,” the company said.
3.54pm: Optus updates Communications Minister and Department
Optus speaks with members of Communications Minister Anika Wells’s staff, and separately calls the Department of Communications to update them on the incident and the planned press conference.
More draft talking points are emailed to Optus’s board.
4.36pm: Optus invites media to press conference
Optus sends invitations to media via email, inviting them to a press conference.
Around an hour later, Optus emails Singtel with the talking points it plans to cover in the press conference.
5.45pm: Optus holds press conference
CEO Stephen Rue fronts the media and apologises for the incident.
5.58pm: PM’s office asks for more information
A senior adviser in Prime Minister Anthony Albanese’s office emails Optus’s head of regulatory and government affairs, requesting “all relevant information on yesterday's outage, which the Department has just informed me about”.
Optus provides an update to a senior adviser of shadow communications minister Melissa McIntosh.
Optus representatives have since told the Senate committee they had conversations with the prime minister's office in the days following the outage.
6.48pm: Singtel informs stock exchange, Optus publishes statement
Singtel files a statement with Singapore’s stock exchange about the Optus incident, just as Optus publishes the statement from its media conference on its website.
8.19pm: SA Premier calls Optus CEO
Returning calls and messages received by his office, SA Premier Peter Malinauskas phones Stephen Rue “to discuss the situation and request further information on fatalities”.
Saturday, 20 September to Wednesday, 24 September 2025
Optus held three further media conferences in the days following the incident, and advised human error had caused the outage.
That was after the company’s CEO had previously said “there was a technical failure in the system, and further, there were no alarms to alert us that some emergency calls were not making it through to emergency services”.
Stephen Rue has since contradicted this, telling the Senate committee the incident was “totally personnel failure" caused by human error, and that key warnings were missed.
Two days after the outage, WA Police also advised a fourth person had died while unsuccessfully attempting a Triple Zero call.
Optus held more board meetings and carried out further welfare checks after seven more affected customers were also identified.
While the company said at the time that Triple Zero calls from 631 customers failed during the outage, it has since revised that number to 455.
It is now facing an investigation by ACMA, further hearings at the Senate inquiry, and an independent review it commissioned into the outage which it has promised to make public.
