That Chinese city that was quarantined?
Well, the officials told everyone that the city was going to be quarantined so if you wanted to get out, you would need to do so now.

Shutting the barn door after telling all the cows to get out...

This outbreak has been happening for far longer.
and, what did the leader of that district do?
He had the largest group buffet in history.
Tons of people in a tight room, with everyone eating out of the same dishes.

This is govern-cement in action.