Police are working to determine whether a fourth person died after being left unable to contact triple zero due to an Optus outage.

Subscribe today for the news that matters

Login or signup to continue reading LIMITED TIME OFFER All articles from our website & app The digital version of Today's Paper Crosswords, Sudoku and Trivia All other regional websites in your area Continue

The deaths of two adults and an infant after efforts to dial through to the emergency number failed during Thursday's 10-hour outage have already been confirmed.

An eight-week-old baby and 68-year-old woman died in Adelaide, while the third fatality linked to the incident, which involved up to 600 attempted triple-zero calls, was that of a 74-year-old from Perth.

WA Premier Roger Cook says

See Full Page