I still have 'responsibility' for those who died in Tiananmen Square, says former student leader "I still feel I have some obligation and responsibility for those persons who died in 1989, or sacrificed their youth" says Wang Dan, one of the most visible student leaders in the Tiananmen Square protests. Three decades on, he recounts what happened, as well as his arrest and imprisonment. Now based in the United States, Wang has not returned to China in 20 years. IMAGES AND SOUNDBITES