How USS San Diego Sank is Still an Open Question 100 Years Later. USS California, renamed USS San Diego in 1914, was a Pennsylvania-class armoured cruiser laid down in San Francisco, California in 1902. Run on two sets of 4-cylinder triple expansion coal-fired engines, she was originally envisioned as a “fast battleship”. However, changes in steam technology rendered San Diego more useful as an auxiliary support to battleships than as a battleship in her own right. She was commissioned at the Mare Island Navy Yard in Vallejo, California on 1 August 1907 and assigned to the Pacific Fleet. San Diego was the largest and only major U.S. warship lost in WWI, sunk on 19 July 1918 off the coast of Fire Island, New York.

https://news.usni.org/2018/07/19/35213