CREATE TABLE table_9577 ("Name" TEXT, "Rank" TEXT, "Tenure" TEXT, "Date of death" TEXT, "Cause of death" TEXT)

What is the Tenure of the Officer with a Date of death of 2001-08-31?
SELECT "Tenure" FROM table_9577 WHERE "Date of death" = '2001-08-31'
SELECT "Tenure" FROM "table_9577" WHERE "Date of death" = '2001-08-31'