Tullibee survived the attacks and continued pursuing the convoy.
Eventually, the submarine closed to approximately 3,000 yards.
Despite the continuing poor visibility, Brindupke decided to fire.
Two torpedoes were launched from the forward tubes.
The crew had committed to the attack.
What happened next took only moments.
history.navy.mil+1
The Torpedo That Apparently Turned Back
American submarines in 1944 generally relied on the Mark 14 torpedo for attacks against enemy ships.
The Mark 14 was a sophisticated weapon for its time.
Powered by a compressed-air propulsion system, it carried a substantial explosive warhead and used mechanical guidance equipment to maintain its intended course and running depth.
Before firing, the submarine's crew entered settings intended to send the torpedo toward a predicted interception point.
Once launched, however, the torpedo operated independently.
There was no remote-control system allowing the crew to redirect it after it left the tube.
If the guidance mechanism malfunctioned, the weapon could depart from its intended course.
One particularly dangerous failure was known as a circular run.
Instead of continuing toward the target, the torpedo began turning and could eventually travel back toward the submarine that had launched it.
For a submerged or surfaced submarine, the consequences could be catastrophic.
A torpedo designed to penetrate and destroy an enemy ship was powerful enough to rupture a submarine's pressure hull.
The crew might have little warning that the weapon was returning.
On the night of March 26, Tullibee launched two torpedoes toward the Japanese convoy.
Approximately one or two minutes later, a tremendous explosion struck the submarine.
The exact underwater trajectory was never observed or reconstructed from recovered physical evidence.
Nevertheless, the timing and circumstances strongly supported the conclusion that one of the torpedoes had circled back.
Kuykendall later explained that the crew had known the positions of the Japanese escort vessels. Based on that information, he believed the explosion had been caused by one of Tullibee's own torpedoes.
The U.S. Navy subsequently accepted a circular-running torpedo as the likely cause of the sinking.