Gene Estess worked on Wall Street for two decades and came to feel that he never had really good days. “I didn’t come home with stories to tell or satisfaction or a feeling I’d done anything to help anybody except myself and my family,” he said in an interview with The New York Times in 2003.

Mr. Estess changed that, however, abandoning the financial world to lead the Jericho Project, which serves homeless, mentally ill and addicted people in Harlem and the South Bronx. He set up a succession of residences and started initiatives that included helping formerly homeless women regain custody of their children.

Mr. Estess died at 78 on April 9 at his home in the Carroll Gardens neighborhood of Brooklyn. The cause was metastatic cancer, his wife, Pat Schiff Estess, said.

His career switch can be traced to a night after work in 1984 when he marched with the multitudes through Grand Central Terminal to catch a train to Westchester County. He noticed a reclining woman with a black poodle among the sea of homeless people who inhabited the station in the mid-1980s. It stuck in his mind.