Retaking of Corregidor
During the re-taking of the island by U.S. forces in 1945, Japanese soldiers who had been trapped in the tunnel after the entrance was blocked as a result of gunfire from USS Converse (DD-509), began committing suicide by detonating explosives within the bowels of the tunnel complex the night of February 23, 1945. The collapsed laterals resulting from these explosions have never been excavated.
Read more about this topic: Malinta Tunnel