The incident comes after Optus was fined A$12 million by regulators for failing to provide emergency call services to thousands during a 2023 outage

Optus, Australia’s second largest telecoms carrier, said on Sunday that a departure from regular processes on a network upgrade sparked a technical failure that disrupted emergency call services for 13 hours and has been linked to four deaths.

There has been growing outcry in Australia over the glitch, which Optus said occurred during a network firewall upgrade from 12.30am on Thursday until about 1.30pm and potentially impacted 600 customers.

The government on Friday said it would investigate the company’s “unacceptable” failure, and Optus said the next day it would cooperate with any effort to look into the incident.

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