John I. Mathewson was born on April 22, 1918. He was the son of Lavens J. Mathewson and Laura Irwin Mathewson. John served in the U.S. Army during World War II as a Captain in the 1st Engineer Special Brigade. He was killed during the Exercise Tiger--one of the large-scale rehearsals for the D-Day invasion of Normandy. This took place in April 1944 in Slapton Sands, Devon in the UK. An Allied naval convoy involved in the exercise was attacked by German submarines, and coordination and communication problems resulted in friendly fire deaths. At least 749 American servicemen were killed. Because of the impending invasion of Normandy, the incident was highly classified and the full story did not come out until years later after the war. He died on April 28, 1944 and is now buried in Golden Gate National Cemetery, San Bruno, San Mateo County, California, USA.