Visitors line up to visit the Memorial Hall of the Nanjing Massacre in Nanjing, Jiangsu, China on Dec. 13, 2009.  On Dec. 13, 2009, thousands of people visited The Memorial Hall of the Nanjing Massacre in Nanjing, Jiangsu, China, to remember those who died at the hands of Japanese soldiers in 1937-8.  The day marked the 72nd anniversary of the start of the massacre. The historical account has always been mired in controversy, and differing opinions on what actually happened have been a consistent obstacle to relations between China and Japan.  China's official account of history states that 300,000 people were killed by Japanese forces over a 6-week period starting Dec. 13, 1937