I'm currently wondering if anyone on here remembers any past occasions (between the years 1945 and 2020) where lockdowns (local or national) of any sort were imposed, and for what reasons?

My most recent recollection is Tuesday 9th August 2011 when our town centre was locked down as a precautionary measure at the height of the riots when both Birmingham and Wolverhampton city centres were being turned over, though both our town, and the county of Staffordshire as a whole (even the Stoke area) luckily escaped said disturbances unscathed.

Any other instances anywhere, for whatever reason?

Just curious?