CREATE TABLE table_16693 ("Rd." FLOAT, "Grand Prix" TEXT, "Date" TEXT, "Location" TEXT, "Pole Position" TEXT, "Fastest Lap" TEXT, "Winning Driver" TEXT, "Constructor" TEXT, "Report" TEXT)

What event was in detroit?
SELECT "Grand Prix" FROM table_16693 WHERE "Location" = 'Detroit'
SELECT "Grand Prix" FROM "table_16693" WHERE "Location" = 'Detroit'