The eyes of Lt. Kermit Tyler turned to what he saw on his screen: a large blip 132 miles north of the Hawaiian island of Oahu.
It was just after 7:02 am, and the skeleton crew working the night shift at the Aircraft Information Center at Fort Shafter were also mystified by the reading that had caught Tyler’s eye.
Could their radar equipment be malfunctioning? How many planes were coming in?
And most importantly – were they American?
It was December 7, 1941, and the world would soon be shocked by the fatal events that followed, which drew the United States into World War II.
Meanwhile, as those American crews watched their radar, a small 40-ton submarine known only by its assigned battle number, HA-19, was cutting through the waves nearby, Bill Newcott wrote for National Geographic.
Even before the first Japanese bomb fell on Pearl Harbor, the HA-19 and four other Kō-hyōteki-class Type A midget submarines were intended to strike the first blow at the “sleeping giant” in the harbor.
However, many did not get that far.
“Because the small subs had to surface frequently for fresh air, four of them were spotted by patrol vessels and destroyed with depth charges,” Newcott wrote.
It was here – just outside the edge of the harbor – that the first spirited American defense of the Pearl took place – not by fierce and modern destroyers, but by the USS Ward, a Wickes-class destroyer from an apparently bygone era – the ship hit the water for the first time in 1918.
Tragically, however, an incident report from Ward’s crew was ignored. If it had, the United States would not have been caught so off guard by the attack on Pearl Harbor.
“I was not at all sure that this was a real attack,” Admiral Husband E. Kimmel, commander in chief of the US Pacific Fleet, later said of Ward’s report.
According to the Naval History and Heritage command, at least one of the midget subs was able to enter the harbor before it was sunk there by the USS Monaghan.
The HA-19, on the other hand, never came close.
Ensign Kazuo Sakamaki and Chief Warrant Officer Kiyoshi Inagaki, the two-man crew aboard HA-19, had difficulties from the start. Their gyrocompass malfunctioned, and they spent the early hours of December 7 bumping into rocks and coral reef outside Pearl Harbor.
In fact, when the Japanese bombing began, HA-19 could be found there – stuck.
According to the National Museum of the Second World War, it was there that the USS Helm spotted the ship that stopped and opened fire.
“The shells fell close enough to knock Sakamaki unconscious as Inagaki pulled the submarine out of trouble. After pulling themselves together, the pair made more attempts to enter port, battering the submarine’s bow to the point that the torpedoes would no longer fire. Seawater poured in through the crushed nose of the HA-19, which was now slowly drifting out. the toxic fumes,” the museum wrote.
With no chance of survival inside the doomed ship, the two men decided to abandon ship and prepared to engage in hand-to-hand combat to the death once on shore.
But before they could, the fumes overcame the pair, knocking them unconscious. They woke up that evening, after missing the attack on Pearl Harbor.
Only Sakami made it to shore alive. Inagaki sank after trying to throw an explosive charge to destroy the midget sub.
Crawling on the ground, Sakamaki soon faced American gunfire. He asked to be killed, but the GIs refused to agree.
Thus, Sakamaki achieved the dubious distinction of becoming the first Japanese surveillance prisoner of World War II.
Since that infamous day, four of the five Japanese midget submarines have been found, with the HA-19 currently on display in Fredericksburg, Texas at the National Museum of the Pacific War.
Some historians argue, controversially, that one of the midget submarines managed to fire its torpedoes at the USS Oklahoma or the USS West Virginia and may still be lurking under the depths of the harbor.
Even so, “You have 300 planes in the sky and five midget subs,” Robert Citino, senior historian at the National WWII Museum, told History.com. “Even if each had a direct hit, there were many more artifices flying in the air than flying under the seas. In the shadow of this, submarines become a footnote.”