Milika Fields, a 2-year-old boy and an 18-year-old man, all San Francisco residents, were injured by the gunfire and taken to San Francisco General Hospital where Fields died, according to San Francisco police Sgt. Neville Gittens. The 2-year-old boy's twin brother was also in the minivan, but was not injured in the shooting.
The toddler and teenager's injuries appeared to be non-life threatening, Gittens said.
Reports of the shooting brought officers to the U.S. Highway 101 offramp at Mission Street and Duboce Avenue at about 7:15 p.m. where they found a silver Mazda MPV minivan riddled with bullet holes.
Fields had been driving the minivan on Highway 101 and was at the offramp when the shooting occurred. She then took the offramp and crashed into a San Francisco Municipal Railway bus, according to Gittens.
A motive for the shooting has not been determined.
Gittens said the suspect vehicle was occupied by two black females and two black males.
Police are asking anyone who may have seen the shooting to call the Police Department's anonymous tip line at (415) 575-4444.
The shooting was the second homicide to occur in the city within a three-hour period Saturday evening, but there was no evidence to show the incidents were related, Gittens said.
Around 5 p.m. Juan Rodriguez, a 34-year-old Daly City resident, was shot near Interstate Highway 280 at Huron Avenue and Laura Street, according to police.
He was also transported to San Francisco General Hospital, where he was pronounced dead shortly before 5:30 p.m., police said.