NANJING, March 6 (Xinhua) -- Chen Guixiang, one of the Nanjing Massacre survivors, passed away on Tuesday at the age of 99. This sad event has brought the total number of registered survivors down to 36, according to the Memorial Hall of the Victims in Nanjing Massacre by Japanese Invaders on Wednesday.

The Nanjing Massacre took place when Japanese troops captured the city on Dec. 13, 1937. Over the course of six weeks, they killed approximately 300,000 Chinese civilians and unarmed soldiers in what is deemed as one of the most barbaric episodes of World War II.

After the Japanese seized Nanjing, Chen saw Japanese soldiers kill her grandmother. In 2011, she went to Japan to testify on the atrocities committed by Japanese troops during the war.

The Chinese government has preserved the survivors' testimonies, recorded in both written and video transcripts. The documents on the massacre were listed by UNESCO in the Memory of the World Register in 2015.