Plainly dressed in a dark gray suit, 87-year-old Xia Shuqin seemed no different from any other suburban Chinese woman. However, her weatherworn face and her determined eyes suggested that her story was different: She had survived the Nanjing Massacre.

It was Dec 13, 1937. "Around 9 or 10 am, the Japanese invaded our house," Xia said. "My father was killed immediately after they broke in. My grandparents, my parents, my sisters, everyone was scared and crying. Seven out of nine of my family members were killed."

For the first time, Xia was invited to the United States to film a documentary about the Nanjing Massacre by the University of Southern California Shoah Foundation, a nonprofit organization dedicated to conducting audiovisual interviews with survivors and witnesses of the Holocaust and other genocides.

At a welcome gathering on Sunday, Xia shared her story with the Chinese community in Los Angeles for the first time.

Only Xia and her then four-year-old sister survived. "I was stabbed three times and passed out. When I woke up, I found myself covered with blood," Xia said.

Her legs were trembling but she insisted to stand on the stage for the speech. "I heard my sister crying and looking for our mom. But everyone else had died."

It was not easy for an 87-year-old to travel across the world, but Xia made it in order to preserve her testimony, to let more people know what had happened in Nanjing in 1937, since the Japanese government has been consistently trying to deny the Nanjing Massacre.

In 2015, documents related to the massacre were included in the Memory of the World program of the United Nations Educational, Scientific and Cultural Organization. However, Tokyo kept raising questions about this decision. Japanese Foreign Minister Fumio Kishida said on Oct 14 that Japan had suspended this year's contribution to UNESCO.

The USC Shoah Foundation has been working with the Memorial Hall of the Victims in the Nanjing Massacre by Japanese Invaders since 2012, to document testimonies from survivors.

The documentary is called Two Sides of Survival. With a new 3D technology, this film offers viewers an interactive experience. "When you come in to see her testimony on film, it will feel like she is actually talking to you," said Amanda Pope, director of the documentary.

There are only 113 survivors still alive and the oldest one is more than 100 years old, said Lu Yanming, scholar at the Memorial Hall of the Victims in the Nanjing Massacre by Japanese Invaders. "The work of collecting testimonies will be harder and harder."

"I thought a lot before I came here, considering my age," Xia said, "but I hope the younger generations will remember how much pain the Japanese invaders brought to us, how deeply they hurt us. I hope they will oppose war and cherish peace."