William K. (Bill) Maher Sr., 80, who retired in 1961 as deputy director of the Atomic Energy Commission, died of cardiac arrest May 29 at Fairfax Hospital.

Mr. Maher came to Washington and began his government career in 1940. He was head construction engineer of the War Production Board's munitions program and then joined the War Department official and worked in the synthetic rubber and the munitions programs.

He joined the AEC in 1947 as chief of the construction and engineering branch. He was promoted to assistant director and then deputy director in the mid-1950s.

After retiring from the government in 1961, he was an executive with the H.K. Ferguson Company of Cleveland, and then moved to California as a consultant with the Bechtal engineering company.

During his time with Bechtal, he worked with the engineering team that developed and installed the Bay Area Rapid Transit system (BART) in San Francisco. Mr. Maher retired a second time in 1972.

He lived in Menlow Park, Calif., before returning to this area last year.

He was a resident of Vienna.

Mr. Maher was a native of Trenton, N.J. He was a 1925 graduate of Villanova University, where he played on the varsity football team.

He served with the Army in France during World War I and was awarded the Purple Heart.

He worked in the construction industry in New Jersey, New York, and Connecticut before coming to Washington.

Mr. Maher had been a member of St. James de Chantel Catholic Church in Bethesda and of the Bethesda Country Club.

His wife, dorothy, died in 1975. Mr. Maher's survivors include two sons, William K. Jr., of Houston, Tex., and Jack B., of Vienna; two daughters, M. Patricia Casey of Golden Valley, Minn., and D. Sharon Viljoen of Mill Valley, Calif.; a sister Katherine Moriconi of Trenton, and 11 grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society.