Around 2004, Mr. Maitland asked Mr. Litman to take over the charity that his mother, Virginia Maitland Sachs, had started before her death. Ms. Sachs had married into the Goldman-Sachs family and had been devoted to philanthropy.

Mr. Litman eagerly took the helm of the nonprofit, which was renamed Virginia’s House of Hope. It donated to the homeless, students and young families, and offered college scholarships.

“The fact that he had grown up in poverty and want, he felt a great sense of sympathy for the poor and homeless,” Mr. Maitland said. “He was a very compassionate guy.”

Mr. Litman, who was in his mid-50s, lived alone and had recently considered renting out part of his home to make extra money, Mr. Maitland said. The authorities did not say if others were inside the house at the time of the fire.

On Monday afternoon, his block was cordoned off with police tape. Gospel music played nearby, and a sign that read “Hope” hung in one of Mr. Litman’s windows.

People passing by praised his altruism. One mentioned that Mr. Litman had bought hoverboards as gifts for young neighbors; another said he had once paid for a “Star Wars”-themed birthday party for a resident’s son.

Around the corner, at Imani Caribbean Kitchen and Bar, Lisa Boone, 50, and her friend Angela Panton, 50, each raised a glass to Mr. Litman.