A public prayer service for Walter Poirier, a University of Notre Dame graduate and Peace Corps worker who has been missing for two months in Bolivia, will take place at 6:30 p.m. Tuesday (April 24) in Copley Square in Boston.p. Organized by the Notre Dame Club of Boston, the service will be led by Rev. John McCarthy, C.S.C., a 1948 Notre Dame graduate. Among those attending will be friends and family from Poirier’s hometown of Lowell, Mass., as well as Notre Dame alumni and representatives from Boston College.p. A 2000 graduate of Notre Dame, Poirier was working on an eco-tourism project for the Peace Corps when he disappeared. Bolivian officials overseeing his mission report they last heard from him Feb. 22.p. The FBI agreed this week to send an agent to Bolivia to assist in the search.