The 1989 massacre at Tiananmen Square was one of the most heart-wrenching displays of state suppression of peaceful assembly in recent history. Following the death of pro-reform Communist leader Hu Yaobang on April 15, 1989, thousands of Chinese students gathered in Beijing's Tiananmen Square to march in his memory. Within days the gathering had transformed into a mass demonstration against corruption in the government, with calls for democratic reforms. The students were joined by civil workers, intellectuals, and public servants; at the height of the protests, up to a million people assembled in the Square. By mid-May protests had spread to 400 cities. After several failed negotiations to persuade the protesters to leave, the government resolved to use force. Soldiers and tanks from the People's Liberation Army were deployed to take control of Beijing and clear Tiananmen Square on June 3-4. The PLA opened fire on the crowds, killing hundreds to thousands of civilians. The exact number is unknown because the Chinese government has never released official death toll figures or allowed outside investigations. James R. Lilley was the U.S. Ambassador to China during the demonstrations. He discusses the military crackdown and how Washington tried to salvage bilateral relations.