What is the 123 south broad street address name before 1973?
CREATE TABLE "tallest_buildings" (
  "rank" text,
  "name" text,
  "height_ft_m" text,
  "floors" real,
  "year" real,
  "address" text
);
SELECT "name" FROM "tallest_buildings" WHERE "year"<1973 AND "address"='123 south broad street';