Lieutenant Teófilo Marxuach was the officer of the day at El Morro Castle on March 21, 1915. The "Odenwald", built in 1903 (not to be confused with the German World War II war ship which carried the same name), was an armed German supply ship which tried to force its way out of the San Juan Bay and deliver supplies to the German submarines waiting in the Atlantic Ocean. Lt. Marxuach gave the order to open fire on the ship from the walls of the fort. Sergeant Encarnacion Correa then manned a machine gun and fired warning shots with little effect. Marxuach fired a shot from a cannon located at the Santa Rosa battery of "El Morro" fort, in what is considered to be the first shot of World War I fired by the regular armed forces of the United States against any ship flying the colors of the Central Powers, forcing the "Odenwald" to stop and to return to port where its supplies were confiscated. The shots ordered by Lt. Marxuach were the first fired by the United States in World War I. The "Odenwald" was confiscated by the United States and renamed "SS Newport". It was assigned to the U.S. Shipping Board, where it served until 1924 when it was retired.