 His later film appearances included roles in "...tick...tick...tick..." (1970), "The Wild Country" (1970), "Vanishing Point" (1971) and "Ulzana's Raid" (1972).Swenson was married to actress Joan Tompkins.Swenson died of a heart attack at Charlotte Hungerford Hospital in Torrington, Connecticut on October 8, 1978, shortly after filming the episode in which the "Little House on the Prairie" character Lars Hanson died, the episode airing on October 16, 1978, eight days after Swenson's death.