Australian City Locks Down After 10 Months Of No Reported COVID Cases

Perth reports its first COVID-19 case in 10 months, prompting a five-day lockdown due to a contagious variant. The city's 2 million residents must stay home until Friday. The last COVID-19 case in WA was reported on April 11th.

What are the residents of Perth required to do during the shutdown?

When was the last reported COVID-19 case in WA State before this incident?