The fire was reported at 9:54 a.m. in a two-story building at 76 Brookdale Ave.
The blaze was controlled at 10:20 a.m., fire officials said.
One person was found inside the home and pronounced dead at the scene from injuries suffered in the blaze, officials said. A young boy was rushed in critical condition to San Francisco General Hospital, where he succumbed to his injuries, fire Lt. Mindy Talmadge said.
There were reports of other residents jumping out of the windows to escape the flames and smoke that broke out on the first floor of the home, Talmadge said.
The cause of the blaze was under investigation Wednesday.