Witnesses told police the woman was sunbathing at Holly Park with a child nearby when a city worker ran over her around 2:20 p.m. The child was not hurt. The woman was transported to San Francisco General Hospital with life-threatening injuries where she later died.
Police later found and detained the driver at Crescent and Agnon avenues.
Holly Park is located near Highland Avenue in the city's Bernal Heights neighborhood. That's near the junction of Highway 101 and Interstate 280.
Watch ABC7 News for the latest details on this developing story.