The attack on Pearl Harbor was launched without a declaration of war by Japan and resulted in a huge loss of life and the destruction of many naval vessels of the US Pacific Fleet. Following the two attack waves, all of the US battleships in port were destroyed or heavily damaged, although five were refloated and eventually returned to service after being repaired, an outcome which probably would not have been possible had the ships been attacked in deeper waters. Despite temporarily crippling the US Pacific Fleet and inflicting over 2,400 deaths, the Japanese attack crucially spared the US Pacific Fleet’s three aircraft carriers, which were already deployed elsewhere. Additionally, the attacks did not significantly damage the vital infrastructure of the naval base. The Japanese did consider a third wave attack against oil storage facilities and dry docks, a blow from which it would have taken the US Navy a lot longer to recover.