Advocate staff photo by ELIOT KAMENITZ--Sister Grace Mary Flickinger , SBS, crosses herself after giving a prayer at St. Katharine Drexel Preparatory, formerly known as Xavier University Preparatory School, during the school's 100th birthday celebration in New Orleans, La. Sunday, Sept. 27, 2015. Xavier Prep was established in 1915 by Saint Katharine Drexel. It was closed in 2013. Alumni then purchased the school building and reopened it as St. Katharine Drexel Preparatory School the same year.