Also incompetence of the Navy leadership (but that is easily seen from the rearview mirror),,,,
Lots of Heroes that day. Many unrecognized.
And a turning point for the Navy, as the Battleships were destroyed or damaged, and the newfangled Carriers (which were not in harbor and therefore not sitting ducks) were undamaged.
But remember those who Served that day as well. They did their job, thinking it was peacetime, even if they were unaware that they were about to go to War.