SAN FRANCISCO—San Francisco residents are mourning the passing of Vivian Brown—one of two twin sisters who had become local celebrities over the years by walking through the city's streets in matching high-end outfits, identical hairdos and cheerful smiles.

Barbara Farber, director of development for Jewish Family and Children's Services, told the San Francisco Chronicle ( http://bit.ly/WOxyf3) that the 85-year-old Brown died in her sleep on Wednesday at an assisted care facility in the city.

Vivian's twin—Marian Brown—told The Chronicle in August that Vivian suffered from Alzheimer's disease, and that after a fall in July, had been admitted into doctors' care.

San Francisco Mayor Ed Lee issued a statement saying the city was "heartbroken by the sudden passing of Brown."