HOW DID THE OUTAGE UNFOLD?
* A firewall upgrade is initiated by Optus at 12.30am AEST on Thursday
* The upgrade blocks calls for Optus users in South Australia, Western Australia and the Northern Territory
* A customer calls the Optus contact centre directly about 9am to complain triple zero calls are not working
* Telecommunications Industry Ombudsman also refers complaints about the failure to Optus
* These calls were not handled "as would be expected", based on early review
* Optus becomes aware of the "severity" of the issue about 1.30pm after another customer contacts the company directly
* SA Police contact the company about 1.50pm to report triple zero calls are not working
* The upgrade is cancelled around that time and service is restored after more than 13 hours
WHAT HAS BEEN THE FALLOUT?
* Optus chief executive Stephen Rue reveals at a snap press conference on Friday afternoon that three deaths have been linked to the outage
* About 600 triple zero calls were "potentially impacted", with some not going through
* Mr Rue apologises and defends delay in informing governments and the public, saying the telco was focused on welfare checks and determining facts
* SA police confirm an eight-week-old boy from Gawler West, north of Adelaide, and a 68-year-old woman from the Adelaide suburb of Queenstown died
* A 74-year-old man from the Perth suburb of Willetton also lost his life
* Federal Communications Minister Anika Wells on Saturday says the Australian Communications Media Authority (ACMA) will run an independent investigation
* WA Premier Roger Cook confirms on Saturday afternoon that another man, a 49-year-old from the Perth suburb of Kensington, died after attempting to call triple zero
* Optus acknowledges the latest potentially linked death and vows to appoint an independent expert to review "every aspect" of the incident
* SA Police on Sunday declare the outage is "unlikely to have contributed" to the eight-week-old boy's death as his grandmother immediately used another phone to contact triple zero after an initial failed call
HAS THIS HAPPENED BEFORE?
* Optus did not provide emergency call service access for 2145 people and failed to conduct 369 subsequent welfare checks during a nationwide network outage on November 8, 2023. It was fined more than $12 million
* A 90-minute Telstra network disruption on March 1, 2024 led to 127 calls not being transferred. It was fined $3 million
* The 2023 Optus outage prompted the federal government to launch a review, led by former ACMA deputy chair Richard Bean
* The review made 18 recommendations in March 2024, including a comprehensive testing regime and mandatory rules for communicating with customers
* All recommendations were accepted by the federal government
Australian Associated Press
