It is a little known fact that the first shots fired by the
United States in
World War 2 occured before the Japanese had fired a single torpedo or dropped their first bomb at
Pearl Harbor.
On the morning of December 7, 1941, the crew of the destroyer USS Ward spotted a Japanese Type A midget submarine trying to sneak into Pearl Harbor behind a cargo ship. The Ward attacked the submarine with its 4-inch guns and depth charges. The depth charges were set to explode at a depth of 100 feet, while the submarine was on the surface. While the 46 ton sub was not damaged by the depth charge attacks, the pressure waves created by the explosion lifted the sub clear out of the water. The sub did not fare so well against the Ward's guns, as one of the 4 inch shells struck the sub's conning tower. The shell did not explode, but water entering through the hole it created caused the sub to sink.
In fact, the Japanese Navy had sent a total of five of the midget subs towards Pearl Harbor. Each of the two man subs, 78 feet long and 6 feet in diameter, was launched from a larger submarine. Each armed with two torpedos, their mission was to sneak into Pearl Harbor in advance of the air raid, finish off any large warships still afloat, and return to their motherships waiting for them off the coast. In fact, none of the five subs made it back to its mothership. One ran aground on December 8, and its captain became the first POW taken by the US in WW2.
Many in the Japanese Navy advocated not using the midget subs in the attack, for fear that it might cost them the element of suprise. In fact, this nearly happened not once, but twice. Before the USS Ward attacked the sub trying to sneak into the harbor by following a cargo ship, the Ward was sent to investigate a periscope sighting by the crew of a minesweeper in the harbor. Upon arriving at the scene, however, the Ward found no evidence of the sub and returned to its patrol.
The worst fears of those who advocated not using the midget subs were avoided, however, by the US command's discounting of the Ward's report. The air raid arrived and struck the unsuspecting US forces, and the rest, as they say, is history.