The medical examiner's office identified the woman as Jon Kong, of San Francisco.
Kong was struck at about 8:15 a.m. by a white van that had been traveling south on Ninth Avenue and turned onto eastbound Geary Boulevard, according to police spokesman Officer Samson Chan. No one else was hurt.
Kong was taken to San Francisco General Hospital but was pronounced dead about 30 minutes later.
The driver of the van, a 50-year-old San Francisco man, stopped and was interviewed by police but not arrested, according to Chan.
The man was a licensed driver and was not intoxicated, Chan said. An investigation into the crash is ongoing.
Willy Wong, the manager of a Shell gas station located at the intersection, said Thursday he heard a loud "bang" and then saw a woman on the ground, run over by the van's two front tires.
Two customers from the gas station went to try to help her, but the woman was not moving. Wong said he believed the woman was in the crosswalk when she was struck, and was then thrown about 20 feet.