The United States was not at war with Germany, even though it was clearly aligned with the democratic side after the Atlantic Conference. It was also providing substantial ‘Lend Lease’ material support to both the United Kingdom and Soviet Russia.
In a more active role, the US Navy and the US Coast Guard became increasingly important participants in the Battle of the Atlantic, escorting convoys across the western Atlantic. They had established a significant Naval base in Iceland for this purpose.
When U-boat U-568 attacked Convoy SC-48, bound from Canada to England, on 16th October, the USS Kearney was ordered to assist with the escort.
During the night of 16/17th U-boat U-568 repeatedly found a destroyer passing between itself and the convoy, preventing an attack on the merchant ships. Its two-stack profile made it most likely a USN destroyer, especially since it was operating west of Iceland.
U-568 launched a spread of torpedoes at the destroyer.
