Optus’ triple-zero outage has been linked to three deaths across the country, but how does the emergency call system work and what exactly went wrong in the process?

Communications Minister Anika Wells said “confidence has no doubt been shaken” in the country’s emergency service system after the embattled telco was unaware of a major systemic failure that affected more than 600 triple-zero calls over 13 hours on Thursday.

Optus CEO Stephen Rue revealed three people had died the following day, admitting the situation was “completely unacceptable”.

The Australian Media and Communications Authority (ACMA) and Optus have launched separate investigations to determine what happened.

Here’s what we know so far. 

What happens if you call triple zero?

It’s hard to say what went wrong without knowing how the triple-zero network works.

The country’s main emergency service line connects people in need of urgent help with police, ambulance or fire services. 

Telcos are legally obliged to ensure every call to emergency services is connected. 

Once dialling 000 or the secondary line 112, a recorded message plays saying: “You have dialled emergency triple zero. Your call is being connected.” 

Telstra is nominated as the emergency call person, whose operators answer the calls, ask for information and transfer them to the required organisation, whether that is police, ambulance or fire services.

The operators will stay on the line until the call is answered. 

If a caller is unable to speak freely on the phone, the operator will transfer them to an interactive voice response, which will ask them to press 55 if they require emergency help.

In extreme events, like a major bushfire or a storm, there may be short delays due to the high number of calls and callers go into a queue.

What happened with Optus triple-zero calls?

A botched firewall upgrade is to blame for an outage that failed to connect more than 600 emergency calls across NSW, South Australia, Western Australia and the Northern Territory between 12.30am and 1.30pm on Thursday.

The deaths of three people, two men aged 49 and 74 in Western Australia and a 68-year-old woman in South Australia, were linked to the outage. 

Optus was unaware of the outage, which did not affect regular calls, for 13 hours. 

“As we had not detected the triple-zero failures in our network at the time of these calls, there were no red flags for the contact centre to alert them to any live issues,” he told the media yesterday.

ACMA chair Nerida O’Loughlin said Optus did not alert her agency or other stakeholders until the matter was resolved, which contradicts the typical process.

She said the authority expects to receive multiple emails per day “as soon as the telco is aware that something has gone wrong”. 

Instead, ACMA received an email that the outage was affecting 10 calls about 3pm on Thursday and did not hear anything more until 3.40pm on Friday.

It was told that the outage actually affected 100 calls, and about 20 minutes later, that figure was adjusted to over 600 calls and three deaths.

“The emails we received on Thursday were perfunctory and some were inaccurate,” O’Loughlin said today. 

At a press conference alongside O’Loughlin, Wells said Optus had “failed the Australian people”. 

Wells said Optus will face “significant consequences” and be “held to account” after its second major triple-zero outage in about two years.

The telco was forced to pay $12 million after a technical issue left more than 2000 people unable to ring triple zero in 2023.

Any potential penalties Optus faces will be financial rather than criminal.

“I won’t speculate on the size of penalties because they are complicated, in terms of number of contraventions but there are $19,000 per infringement notice and the court can impose up to $250,000 per contravention,” O’Loughlin said today.

“The financial penalties we can also seek enforceable undertakings from Optus to take specific, actionable steps to improve their processes.”

Prime Minister Anthony Albanese said he would “not be surprised” if Rue, who became CEO in November after his predecessor Kelly Bayer Rosmarin departed following fallout from the 2023 outage, also lost his job.

Optus is implementing a new compulsory escalation process if anyone reports issues to triple zero through the customer call centre, and conducting an internal investigation.

The telco is also working with ACMA, which is investigating and will also probe Telstra’s compliance with new communication requirements.

ACMA will hand the government a report and recommendations in due time. 

The outage may also prompt a wider review into the telco industry and emergency service network, as Optus is not the only provider to oversee triple-zero outages.

“We are considering what needs to be done holistically or as part of legislative relief for the Australian people, given their confidence has no doubt been shaken by what has happened here,” Wells said today.