Mother says pain of daughter's death 'will never subside'

"My daughter's suicide bears no relation to her penning of the book," said Ying-Ying Chang, mother of The Rape of Nanking author Iris Chang.

Back in 1997, her daughter Iris published her groundbreaking work on what's known today as the Nanjing Massacre, in which at least 300,000 Chinese civilians and unarmed soldiers were killed by invading Japanese troops during a six-week rampage starting in December 1937.

Iris, a journalism graduate from the University of Illinois and a second-generation Chinese immigrant in the United States, committed suicide in 2004, at the age of 36.