What happened

An automated network shutdown following a routing event disabled Optus mobile, internet and fixed-line services nationwide. More than 10 million customers and about 400,000 businesses depended on the affected network. ACMA found 2,145 people were denied emergency-call access and 369 required welfare checks were not completed; Optus paid penalties totalling more than A$12 million. The outage also disrupted hospitals, electronic payments and Melbourne rail operations. Reviews characterised it as preventable operational failure, not a cyberattack.

When cited sources give different casualty, damage or spill figures for this event, they’re reported side by side above rather than merged into one number. See how confidence levels work.