The second raid on Pearl Harbor

War History Online has an article written by Pat and the team at Hoku Hawai'i, who provide luxury tours on the island of Oahu and cover Pearl Harbor extensively, about a little known action during World War Two:

Everyone knows about the Pearl Harbor attack on 7 December 1941 by the Japanese Imperial Navy. But few are aware of the second raid that the Japanese launched on Pearl Harbor, codenamed Operation K, as a reconnaissance mission of Pearl Harbor, and also intended to delay the salvage operations of the American fleet.
During the first Pearl Harbor attack, the Japanese had missed destroying the oil storage facilities near the Pearl Harbor Naval Air Station and the Naval Yard, so they aimed to bomb these facilities in Operation K and disrupt the repair and salvage operations that were in full swing. This was, perhaps, the longest bombing sortie by two planes without fighter escort during World War Two.
Operation K culminated on 4 March 1942. These flying boats (photo) were huge, with a gross takeoff weight of seventy thousand pounds and a wingspan of over a hundred feet. Four engines powered this flying boat; its top speed was nearly three hundred mph, and it had a crew of ten. Named the Flying Porcupine by Allied pilots, this flying boat was defended by ten machine guns and an equal number of 20mm cannons. The Kawanishi H8K flying boat was capable of undertaking long missions that lasted up to 24 hours. Each flying boat could carry eight five-hundred-pound bombs.
Initial plans of the Navy’s high command called for the use of five H8K aircraft. They were to fly to French Frigate Shoals, the biggest atoll in the northwestern tip of the Hawai'ian islands. Here they’d be refueled by submarines before heading to Pearl Harbor. More raids would be undertaken if the first was successful.
On mission day, only two of the planned five flying giants were available. The first H8K aircraft was flown by Pilot Lieutenant Hisao Hashizume, the commander of the mission. Ensign Shosuke Sasao flew the second H8K. The mission started at Wojte Atoll in the Marshall Islands. Each aircraft was loaded with four bombs. From Wojte, the flying boats flew nineteen hundred miles to French Frigate Shoals. After refueling there, the planes set off for Pearl Harbor, now just five hundred miles away.
The Ten-Ten dock was so named because of it length: 1,010 feet, and the Navy’s salvage and repair efforts were in progress at this dock. The time of the bombing was to be sometime after midnight, however, the Japanese plan of bombing the Ten-Ten Dock was hindered due to the prevalent unfavorable weather conditions at Pearl Harbor. Inclement weather also resulted in a comedy of errors. The Japanese submarine, I-23, that was supposed to direct the flying boats south of Oahu, was lost after 14 February.
Hawai'i’s WARD —Women’s Air Raid Defense— picked up the Japanese planes on radar. They had been working for twelve weeks since the Pearl Harbor attack, and were on high alert. The response to the women’s alert was instantaneous. Searchlights were turned on, fighter planes were scrambled, and anti-aircraft guns were manned. Since it was a moonless, rainy night, the fighter planes were not successful in downing the flying boats at an altitude of 15,000 feet, even with help from the WARD operators.
In the absence of position support from submarine I-23, the Japanese pilots used the lighthouse at Kaena Point for a position fix. Mission Commander Hashizume attacked from the north. Poor quality radio communication resulted in the second pilot, Sasao, turning to skirt the opposite (north) coast of Oahu. In the inclement weather, Hashizume was able to see just some patches of the island. He dropped his bombs on the Tantalus Peak sometime around 2 am local time. The bombs landed close to Roosevelt High School, but the damage was minimal. (If you’re ever in Hawai'i, there are plenty of Pearl Harbor tours that cover this event and many others that happened during World War Two.)
Sasao dropped the four bombs he carried into the ocean somewhere close to the sea approach to Pearl Harbor and returned to Wotje Atoll. Hashizume, whose aircraft had sustained hull damage at French Frigate Shoals, proceeded to his home base at Jaluit Atoll.
Operation K was a colossal failure. The mission was jinxed right from the beginning. Only two 'porcupines' flew, instead of the planned five. Also, the absence of an element of surprise and poor weather conditions forced the Japanese to drop their bombs blind when they could not sight their targets. The flying giants returned without success.

Rico says a little-known clusterfuck...