In 1989, Beijings Tiananmen Square became the site of large-scale protests, which were crushed by Chinas Communist rulers. The protests were precipitated by the death of pro-reform Chinese Communist Party (CCP) general secretary Hu Yaobang in April 1989, amid the backdrop of rapid economic development and social change in post-Mao China, reflecting anxieties among the people and political elite about the countrys future. After weeks of unsuccessful attempts between the demonstrators and the Chinese government to find a peaceful resolution, the Chinese government declared martial law on the night of June 3 and deployed troops to occupy the square in what is referred to as the Tiananmen Square massacre. On 3 to 4 June, troops began to move towards Tiananmen Square, opening fire, crushing and arresting protesters to regain control of the area. The exact number of casualties is unknown, but estimates range from a few hundred to a few thousand. The events produced one of the most iconic photos of the 20th Century - a man facing down a line of tanks heading away from the square, known as Tank Man. The Chinese government has never acknowledged the true events surrounding the Tiananmen massacre, and discussion of the events is highly sensitive in China, with authorities banning all mention of the protest even today.