The first record of Lucienne is as a small child in her birthplace Geneva, photographed with her brother and sister by her father, the composer Ernst Bloch. Bloch was also a photographer and taught Lucienne how to develop photographs as a child. In 1917, Bloch sailed with his family across the Atlantic to take up a position in New York, and a few years later became director of the Institute of Music in Cleveland and then, from 1925, of the San Francisco Conservatory of Music. He had a somewhat tempestuous relationship with his wife, who after a few years took her children back to Paris.
Lucienne studied at the Ecole des Beaux Arts in Paris, and spent a year making glass sculptures in Amsterdam. Returning once more to the United States, it was in 1931 that she both held a one-man show of her glass in New York and first met the formidable Mexican painters Diego Rivera and Frida Kahlo.
In her diary, Bloch recalled that this was at a dinner in Rivera's honour in New York, where she was seated next to the great man, much to the irritation of the jealous Kahlo, whose first words to the bemused young Swiss woman were: "I hate you."
Soon though, Kahlo became satisfied that Bloch was not infatuated with her husband, and over the next few years, she became Kahlo's faithful companion, accompanying her during the difficult loss of her child, and the death of her mother, and even travelled to Mexico with her. On one occasion, in August 1932, Bloch wrote in her diary: "We took cold chicken in a little basket and went to Belle Isle dragging Diego with us at the last instant. It did him good to go out. He was so surprised at the beauty of the trees when lying down in the grass. He says trees are ugly and nature is hokum, but he can't help admiring it when he's in it."
Bloch herself was a talented sculptor - Frank Lloyd Wright offered her the post of sculpture director at his school in Wisconsin. But she was particularly impressed with the public murals that Diego Rivera was busily creating in Mexico and the United States, and instead became Rivera's assistant. She also fell in love with his chief plasterer, the Bulgarian Stephen Dimitroff.
She helped on Rivera's most controversial projects, at the Detroit Institute of Art, and on Man at the Crossroads, for the Rockefeller Center in New York. Nelson Rockefeller had commissioned the 1,000sqft work, but the Rockefeller family was horrified when it discovered that Rivera intended to make it a paean in praise of Communism, with Lenin as the great spiritual leader of mankind. Rivera was quickly paid off, and armed guards moved in while the mural was covered with screens.
Bloch attempted to defend it, even going so far as to scrawl on the whitewashed windows of the Rockefeller Center: "Workers unite! Help protect Rivera M-" - at which point, she was dragged away. She returned however, on 8 May 1933, with Dimitroff and Kahlo, and while Kahlo distracted the guards, Bloch climbed up on the scaffold and with her camera managed to capture the only images of the mural to survive.
Throughout the 1930s, Bloch continued to work as a muralist and sculptor in glass and terracotta. She and Dimitroff married and became an artistic fresco team, he handling the plaster and she the painting on around 50 projects around America. Her photographs of Frida Kahlo were widely shown, but she also took photos for Life magazine, again demonstrating her strong political convictions, as in the series of striking carworkers in late 1930s. Dimitroff became a union organiser until the couple moved to California in the 1960s.
Towards the end of her life, there was a renewed interest in Lucienne Bloch's work. The singer Madonna, researching for a film project about Frida Kahlo, talked with her at length and set up a fund to preserve the best of her murals, The Evolution of Music, in the George Washington High School in New York. From 1965 Bloch lived in Gualala, California, and it was here that the first exhibition of her photographs of Frida Kahlo was recently held.
Lucienne Bloch, muralist: born Geneva 1909; married Stephen Dimitroff (died 1996; two sons, one daughter); died Gualala, California 13 March 1999.