Optus has suffered another Triple Zero outage, with almost 5000 customers in the Illawarra region of NSW affected on Sunday.
At least nine Triple Zero calls from the Dapto area failed to reach emergency services, forcing one person requiring an ambulance to call on a non-Optus phone while another forwent emergency assistance due to the outage.

Thousands of customers were unable to reach emergency services on Sunday.Credit: Sitthixay Ditthavong
NSW Police conducted welfare checks for four other callers, and also checked in on another person who unsuccessfully attempted to reach emergency services. Two other callers accidentally called Triple Zero.
The issue involved a mobile phone tower in the Dapto area, which affected calls between 3am and 12.20pm on Sunday.
“We have investigated the impact of the issue … and have confirmed with police, all callers who attempted to contact emergency services are OK,” an Optus spokesperson said.
“We sincerely apologise to any customers who were impacted.”

Optus chief executive Stephen Rue.Credit: Sitthixay Ditthavong
Optus is yet to identify the cause of the outage.
It comes as the telco grapples with the fallout from its catastrophic Triple Zero outage earlier this month, which affected customers across South Australia and Western Australia and been linked to three deaths.