Chris’s triple zero calls were met with silence. Now out of hospital, he wants Optus to know lives are at stake

As governments condemn Optus for failing the Australian people, consumers worry the telco has not learned from its previous experience'

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It was about midday on Thursday when paramedics in South Australia realised something was wrong. The state's ambulance service, long strained by huge demand and ramping, was quieter than usual.

About the same time, a 70-year-old man in Adelaide began to panic. Chris Tyndall was struggling to breathe and, having lived through two heart attacks and a quadruple bypass, knew he needed help. He managed to get to his phone and dial triple zero.