Sydney is Australia’s largest population city in Australia’s largest population state of New South Wales.
NSW Health has notified on a fresh COVID-19 case. says that:
Urgent investigations into the source of the infection and contact tracing are underway
case is a male in his 50s
lives in southeastern Sydney
believed to have been infectious since April 30
This should not be too much a cause for concern for a local shut down. NSW’s Premier is one of the saner of the state premiers and will not shut down the city on this. Keep an eye out for more cases, that might change the situation of course.