Roger W. Gronblom, 80, of Plymouth, formerly of Wareham, a Navy veteran of the USS Ault during the Vietnam War, died unexpectedly Saturday, June 20 at Beth Israel Deaconess Hospital–Plymouth. Born in Plymouth to the late Anselm and Dorothy L. (Sterry) Gronblom, he graduated from Wareham High School in 1964, where he participated in track and cross country and was also a member of the school choir. Following graduation, he enlisted in the U.S. Na…