Conversation so far:
where did the attack on pearl harbor occur
The attack on Pearl Harbor occurred in Honolulu, Hawaii
When was the attack on pearl harbor
It was on Sunday morning, December 7, 1941
Who was responsible for the attack on pearl harbor
The Imperial Japanese Navy Air Service is responsible for the attack on pearl harbor

Question: how many civilian casualties
Self-contained rewrite: how many civilian casualties occurred during the attack on pearl harbor