The oldest survivor of the Nanjing Massacre died on Sunday, and fewer than 100 survivors remain, the Memorial Hall of the Victims in the Nanjing Massacre said on Monday.

State leaders will attend a public memorial ceremony at the Memorial Hall of the Victims in the Nanjing Massacre by Japanese Invaders on Wednesday.

Guan Guangjing died at age 100 three days before the National Memorial Day for Nanjing Massacre Victims. He had been bedridden for six months because of heart disease and died at home from multiple organ failure, his 76-year-old son-in-law, who gave only his surname as Liu, said by phone.

Guan contributed verbal testimony to Irrefutable Evidences, A Memoir of the Lishui Bombing Caused by Japanese Invaders, published by Nanjing Press in November 2016. The book collected 31 survivors' oral accounts of the bombing in Nanjing's Lishui county on Nov 29, 1937, and took more than 1,200 lives.

He said in the book that he hid under a big rock during the bombing and witnessed his neighbors, including the four generations of a family surnamed Sun, being killed.

Guan later managed to stay alive by hiding wherever he could during the massacre, in which more than 300,000 Chinese were killed by Japanese invaders, when Nanjing, then China's capital, was occupied in December 1937.

Officials from the memorial hall said Guan narrated that he witnessed Japanese invaders killing people multiple times.

The National Memorial Day falls on Dec 13, and this year marks the 80th anniversary of the Nanjing Massacre.

"Guan was an orphan before 1937 and had no siblings. Five years ago, his wife died at age 84," Liu said.

Internet users mourned for Guan after the memorial hall announced his death on Sina Weibo on Sunday.

The Weibo post said Guan used to be a barrel maker in Lishui county and lived a frugal life. He was always willing to help others and was highly esteemed in the local community, it said.

It also said his family donated several of his personal articles to the memorial hall, including a paper fan, a watch and a teapot.

Zhang Sheng, a history professor at Nanjing University, said only about half of the more than 90 survivors can express themselves clearly as most are older than 85.

Wu Lisong, a history lecturer at Nanjing University, said the public used to believe that the survivor's pain would pass but have come to realize that it lasts a lifetime.

"Some of them are stricken with fright when people wearing Japanese military uniforms appear on the TV screen, and some become irritable whenever people mention those years to them," said Wu, who since September 2016 has led a project collecting oral accounts from survivors.

"Neither an apology nor compensation can reverse the traumas to the victims and survivors, but we still must make clear the history, which may be a starting point of reconciliation," he said.

Contact the writers at [email protected]