CREATE TABLE table_74115 ("Team" CLOB, "Outgoing manager" CLOB, "Manner of departure" CLOB, "Date of vacancy" CLOB, "Replaced by" CLOB, "Date of appointment" CLOB, "Position in table" CLOB)

What was the manner of departure for the appointment date of 21 september 2010
SELECT "Manner of departure" FROM table_74115 WHERE "Date of appointment" = '21 September 2010'
SELECT "Manner of departure" FROM "table_74115" WHERE "Date of appointment" = '21 September 2010'