CREATE TABLE table_17137 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production code" CLOB, "U.S. viewers  ( millions ) " CLOB)

When was the show first aired that was viewed by 3.57 million U.S. viewers?
SELECT "Original air date" FROM table_17137 WHERE "U.S. viewers (millions)" = '3.57'
SELECT "Original air date" FROM "table_17137" WHERE "U.S. viewers (millions)" = '3.57'