Here "city" represents the people living in the city. Alternate translation: "The people of every city" (See: [[rc://en/ta/man/translate/figs-metonymy]])
These two clauses have similar meanings. The second one strengthens the thought in the first. Alternate translation: "The cities will be empty. There will be no one left to live in them" (See: [[rc://en/ta/man/translate/figs-parallelism]])