A failed emergency call during a widespread Optus outage is unlikely to have cost a baby boy his life, police say.
A botched firewall update on Thursday blocked hundreds of calls to triple zero in South Australia, Western Australia and the Northern Territory.
An eight-week-old boy from Gawler West, north of Adelaide, was among four deaths authorities had linked to the fault.
While the boy’s family was impacted, police now believed the outage is “unlikely to have contributed to the death”.
“The deceased boy’s grandmother has told investigating police that she attempted to call 000 using her mobile phone when she was alerted to the fact her grandson was not breathing,” SA Police said in a statement on Sunday.
“When her call was not connected, she immediately used another mobile telephone in the house and was successfully connected to 000.
“The preliminary investigations indicate the child’s death is not due to any delay in (SA Ambulance Service) attending the Mulga St house, despite the failure of the first attempt to call 000.”
SA Police said an investigation into the death of a 68-year-old Queenstown woman was “more complex”, with work continuing to determine the impact of the outage.
The deaths of two Perth men, a 74-year-old from Willetton and a 49-year-old from Kensington, are also being probed over the fault.

Optus was not aware of the “severity” of the outage until being notified by a customer about 1.30pm, Optus chief executive Stephen Rue said.
The update was cancelled and access to the emergency line was restored after 13 hours.
Optus had also been contacted by the telecommunications industry ombudsman about two complaints from people trying to inform the company about the outage.
“Early review suggests that we had not handled these calls as would be expected,” Mr Rue said.
“Optus will be appointing an independent person to lead a review into this entire incident from every aspect.”
Queensland Premier David Crisafulli was briefed on the fallout by the state’s top cop Steve Gollschewski on Sunday.
Although the commissioner was “confident” Queenslanders weren’t impacted, Mr Crisafulli said a system “deep dive” was underway and his state government would reach out to Optus.
“With great profits come great responsibility, and we’re asking all of them (telcos) to do better,” he told reporters.
The federal coalition is calling for a broader independent investigation into the triple zero network, on top of reviews orchestrated by Optus and the Australian Communications Media Authority.

Nationals leader David Littleproud said the behaviour of Optus, as a universal service provider, was “abhorrent”.
“The fact that Optus has just in some blasé way ignored the risks that are there for Australians to be able to ring triple zero is just beyond belief,” he told Nine’s Today on Sunday morning.
“They do need to face penalties for this, the government needs to crack down.”
SA Premier Peter Malinauskas said it took a call from him to the Optus CEO before the problem was fixed.
“The lack of information flow from Optus to the South Australian government’s appropriate authorities is somewhat bewildering and it raises a lot of questions,” he said.
Federal Communications Minister Anika Wells slammed the telco for failing to heed the recommendations of a review into a November 2023 outage when customers were also unable to contact triple-zero.

“Many of the things that happened in this outage are failures to implement some of those recommendations, including alerting the public or emergency services authorities,” she said.
Mr Rue defended not publicly revealing the outage until Friday night in a snap press conference more than a day after the problem was identified and rectified.
He said Optus was focused on determining the facts and conducting welfare checks before informing governments and the public.
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