I think that is the next step in the official escalation plan https://www.seattletimes.com/seattle-news/health/seattle-area-official-outlines-potential-next-st

I think that is the next step in the official escalation plan https://www.seattletimes.com/seattle-news/health/seattle-area-official-outlines-potential-next-steps-in-coronavirus-response-including-cancellation-of-events/ https://www.seattletimes.com/seattle-news/health/seattle-are... There is very little precedent I could find, however baltimore did impose a curfew in 2015 for a short period of time.