This was standing in Lindenwood Park here in Fargo, North Dakota. It's a memorial to the World War 2 submarine, USS Robalo.

The Robalo was a Gato-class submarine launched in 1943 and completed three patrols in the Pacific theater. Its final patrol led to its destruction, sunk by mines off the Philippines on July 26, 1944. All crew but four died. Those surviving four crewmen were captured and imprisoned by Japanese soldiers. After being held in a POW prison, these four survivors were taken from the Philippines by a Japanese destroyer on August 15. To this day, the fate of that destroyer and the four survivors remains unknown.