I had a supply of stone on one side of the map, with some masonry workbenches nearby, but my townies prefered to use the first built masonry benches clear across the map. So after some used it I deleted the zone under them so they had the red 'x' over them and wouldn't be used. However, 4 townies were still headed for those benches and when they got there they became stuck on them. I watched them for about a minute and they never moved. So I deleted the workbench from under them and they went on carrying their stone to the working benches like normal. But had I not deleted the non-working benches, I wonder how long they would have stayed.