Edmund Joseph Fitzgerald, 100, a retired government auditor who was active in Catholic organizations, died of pneumonia June 18 at his home in Falls Church.

He came to Washington and began his government career in 1936 as an internal auditor with the Reconstruction Finance Corp. and retired in 1967 from the Interstate Commerce Commission.

Mr. Fitzgerald was a longtime member of the Catholic Cathedral of St. Thomas More in Arlington, where he had been an usher, served on the men's council and belonged to the St. Vincent de Paul Society. He also was a past president of the Serra Club of Northern Virginia, an organization promoting vocations to the priesthood, and a member of the Secular Franciscan Order.

He was born in West Haven, Conn., and was a 1928 graduate of the College of the Holy Cross. He served with the Army in the Mediterranean theater during World War II.

He was a past president of the Holy Cross Club of Washington and a recipient of its highest alumni award, the In Hoc Signo. He was a member of the Ancient Order of Hibernians and the Connecticut State Society.

His first wife, the former Paulette E. Garnier, whom he married in 1945, died in 1968. Survivors include his wife, the former Margaret M. Haider, whom he married in 1972, and two stepsons, Claude C. and Jean-Pierre Garnier, all of Falls Church; seven grandchildren; and 14 great-grandchildren.