SM U-15 was one of the three Type U 13 gasoline-powered U-boats produced by the German Empire for the Imperial German Navy. On 9 August 1914, U-15 became the first U-boat loss to an enemy warship after it was rammed by British light cruiser HMS Birmingham. Constructed by Kaiserliche Werft Danzig, U-15 was ordered on 23 February 1909 and was commissioned three years later on 7 July 1912. The boat left port for its first patrol on 1 August 1914, but on 9 August, U-15 was forced to lie stopped on the surface off the coast of Fair Isle, in Shetland, Scotland, after its engines had failed.