Database: address_1
Question: What is the name of the city closest to Chicago?
SQL:
SELECT T3.city_name FROM Direct_distance AS T1 JOIN City AS T2 ON T1.city1_code  =  T2.city_code JOIN City AS T3 ON T1.city2_code  =  T3.city_code WHERE T2.city_name  =  "Chicago" ORDER BY distance LIMIT 1