CREATE TABLE table_68830 ("Date" CLOB, "Location" CLOB, "Nature of incident" CLOB, "Circumstances" CLOB, "Casualties" CLOB)

Which Casualties have a hostile Nature of incident and Circumstances of mortar attack?
SELECT "Casualties" FROM table_68830 WHERE "Nature of incident" = 'hostile' AND "Circumstances" = 'mortar attack'
SELECT "Casualties" FROM "table_68830" WHERE "Circumstances" = 'mortar attack' AND "Nature of incident" = 'hostile'