Liu was a classmate of Ye Mengyuan and Wang Linjia, both 16, who were killed in the crash July 6 at San Francisco International Airport. All three were part of a group of Chinese students traveling to Los Angeles for a three-week summer camp, the Los Angeles Times reported.
With Lieu's death Friday at San Francisco General Hospital, the death toll from the crash stands at three, China News said. Her name had not been released at the request of her family, the Times said.
San Francisco Police Chief Greg Suhr told the San Francisco Chronicle Ye was run over by a fire truck after the crash but it was not clear whether she was killed in the plane crash or by the fire truck.
"We know for sure she was at least run over one time, but at the time she was under foam, so nobody could have seen her," Suhr said. "And the question is whether or not she was still alive at the time. So the coroner in San Mateo County will be determining that."
Federal investigators say the Boeing 777's automatic controls seemed to be working normally before it crash-landed.
National Transportation Safety Board Chairwoman Deborah Hersman said cockpit tools that help pilots set minimum speed and altitude during landings showed "no anomalous behavior" on the flight.
The pilots said they had set the plane's automated throttle to maintain speed but noticed the speed declining and tried to recalibrate.