J.F. Powers, one of Minnesota's most celebrated authors, died of natural causes at his home in Collegeville on Saturday. He was 81. Powers won national acclaim for his novels which explore the tensions of Midwestern Catholicism by following the story of a small-parish priest. He was considered a quiet literary giant, who worked various jobs in Chicago during the Great Depression and became a conscientious objector during World War II. Powers was a Professor and Writer-in-Residence at St. John's University in Collegeville until 1993.