Ben Horowitz, who guided the City of Hope from a relatively small tuberculosis hospital to a world-renowned cancer and medical research center, has died. He was 96.

Horowitz died Saturday of natural causes at his Los Angeles home, the center announced.

He was a young New York City lawyer dedicated to helping the disenfranchised when he decided to join what became known as the City of Hope, based in Duarte, in 1945.

Instead of reshaping the world, Horowitz told The Times in 1986, he realized he could make a bigger contribution by taking on "just the pasture right behind me."

From 1953 through 1985, Horowitz was chief executive of the City of Hope, shepherding the institution through a dynamic era of growth.

As the center became known for cancer care and cutting-edge research in cancer and other life-threatening diseases, Horowitz took its operating budget from $600,000 to more than $100 million a year.

"Ben Horowitz didn't have a science background, but he understood the promise and potential in basic research and how it could contribute to medical advances," Arthur Riggs, director emeritus of the City of Hope's Beckman Research Institute, said in a statement.

Horowitz once said that he had an easier time drawing respected scientists to the institution after he persuaded Nobel Prize-winning geneticist Hermann Muller to join the City of Hope around 1964.

During Horowitz's tenure, two researchers in the mid-1970s did the basic research for synthesizing human insulin, which transformed how diabetes is treated. Pioneering research in 1984 also led to the development of primary drugs used to treat cancer today.

To make the City of Hope stand apart, Horowitz "came up with the idea of a pilot medical center that handled people with diseases that were not well understood or where treatment was not easy to come by," he said in the 1986 Times article.

By the time he retired at 71, he had overseen the City of Hope's transformation into one of the strongest health facilities in the nation. He continued to serve on its board of directors.

Born March 19, 1914, in Brooklyn, he was the son of Saul Horowitz, a window dresser, and his wife, Sonia.

Horowitz earned his bachelor's degree from Brooklyn College and his law degree, in 1940, from St. Lawrence University in Canton, N.Y., and set out to help those who were "helpless" or hadn't gotten "a fair shake," he later said.

A similar ideological thread, that "health is a human right," drew him to the City of Hope, the center said. His first task was to set up a national fundraising program.

As chief executive, he oversaw the establishment of a bone-marrow transplant program that is one of only six in the country and the creation of the Beckman Research Institute, which spearheads research in life-threatening diseases.

"Ben's foresight and support were so crucial," according to Dr. Eugene Roberts, a former associate research director for the institution, "he could be listed as a coauthor of all papers and scientific findings to come from City of Hope."

Horowitz is survived by his wife of 58 years, Beverly; son Zach Horowitz; daughter Jody Horowitz Marsh; and three grandchildren.

Services will be at noon Friday at Mount Sinai Hollywood Hills, 5950 Forest Lawn Drive, Los Angeles.

valerie.nelson@latimes.com