The first relates an incident in the first twelve months of the war in the Pacific, a period when US submarines were badly handicapped by highly defective torpedoes. But as related, sometimes plain luck is enough to sink an enemy ship.
The (USS) Tambor moving along briskly on the surface at night, fell in with four cruisers and two destroyers, presumably American. By first light, she saw that the warships were Japanese - and they saw her. In the ensuing confusion, two of the cruisers collided. Both were damaged in the crash, and one sank that afternoon without being hit by a single torpedo from the Tambor.
One can only imagine the feeling on the submarine's bridge as the early dawn suddenly reveals their predicament. "Uh-oh" hardly covers it.