Is it possible that there were more casualties than were reported in the attack on Pearl harbor?

The only reason something is impossible; is because someone hasn't done it yet. For this particular question; the only reason it's impossible for casualties to be different is because someone hasn't proven otherwise (yet). During the September attack on NYC in 2001, casualties were (by Televison/radio) initially reported to be as high as 50,000 people. For the student historian: statistics will almost always be different. They will almost always NEVER be accurate. If TWO men are on the same battleground, on the same time and day, during the same event...you will get TWO views of the battle; TWO different reports (after action reports). One or both of those reports will go into the history books.