Mario R. Sonsini was born in 1921 to Mr. and Mrs. Pasquale Sonsini who lived in Coatesville, Pennsylvania. Mario was one of three children. Mario was born in Italy.
Mario attended local schools, and worked at Lukens Steel Company.
Mario joined the Marine Corps July 20, 1941 and served in the Pacific Theater of Operations. He married Florita V. Demaio on June 12, 1943.
Mario’s parents received a telegram from General AA Vandergrift of the Marine Corps informing them that their son has been killed in action on October 25, 1944 in the Central Pacific area - most likely Leyte Island, the most prominent combat action ocurred there during the time of his death.
A military mass was held at Our Lady of the Rosary Catholic Church on November 11, 1944.
His brother James served in the Navy during the war.