Marion Block Anderson,70, a peace activist who took her cause to the Joint Chiefs of Staff by crashing one of their meetings, died Dec. 7 of cancer in East Lansing, Mich.

The threat of nuclear war moved Mrs. Anderson to action, said her son, Dave Anderson. In 1958, she went to the nation's capital and testified before the Joint Committee on Atomic Energy.

On her way to a demonstration against the Vietnam War in Washington in 1970, she changed her mind and asked her taxi driver to take her to the Pentagon.

Mrs. Anderson walked past several guards and into a meeting of the Joint Chiefs of Staff. She handed each of them an anti-war leaflet, left the Pentagon and went to the peace march.