Question

This surprise attack on the largest American naval base in the Pacific, which killed 2403 Americans and injured 1178 more, was known as…

Answer 1

The surprise attack of Japanese kamikaze fighter pilots was known as Pearl Harbor.  

Answer 2

The numbers go all over the place. They vary considerably from 2335 to 2403. It looks to me that 2403 includes civilian deaths which 2335 does not.

1178 may have the same disagreement. This number is also a little higher than the actual number of military personnel. Civilians should be counted. They died as result of the attack.

In any event I think you are talking about the "Day of Infamy" -- December 7, 1941 -- the Attack on Pearl Harbor. I can't think of anything else that would have these sorts of numbers.