@KhanSaba1278 Besides the obvious AirPods, it is unlikely an office would have people sitting at a steel file cabinet or have windows that open like those portrayed in this building which is over 20 stories high.
@Jennifer55gt Assuming the killer is a man or a person you’ll have 32 left since he walked to the room and made it 51-30 adding the killer makes a 32 left in the room alive.
If you count the body, then you’ll have 52 people left in the room with 30 of them dead