'Tower' in the Bible

Jesus began to speak to them [the chief priests, scribes and elders who were questioning Him] in parables: “A man planted a vineyard and put a wall around it, and dug a pit for the wine press and built a tower; and he rented it out to tenant farmers and left the country.

Or do you assume that those eighteen on whom the tower in Siloam fell and killed were worse sinners than all the others who live in Jerusalem?