During flight KE661 was checking out, one of cabin crew informed that her colleague did not come to check out as schedule.
Then I immediately called to her room but no respond. After that I have checked with operator about her wakeup call.
Operator informed me that guest did not respond for wakeup call then he notices to housekeeping attendant to knock the guest room door, but no feedback from housekeeping (without informed Duty Manager before).