Zhang Tieyan, female, 29. Following her graduation from a technical college, she worked as a technician in the Heilongjiang Petroleum Factory (former Lamadian Chemical Factory of Daqing City). On April 19, 2000, her work unit called her from her work to write the so-called "Guarantee Letter." Other people that were called from their work at that time included her husband, Yang Qing, Zhang Zhong and his wife. Three days later they were sent to the Ranghulu District Detention Center because they refused to write the "Guarantee Letter." On May 5, 2000, they were transferred to the detention center in Daqing City. After two weeks, they were still wearing their same work clothes. They were detained there without due process until August 11, 2000 when Zhang Tieyan died.