 Complete the following phrase:  Yaobangs death in April 1989 became the catalyst for the 1989 Tiamen Square protests, during which people called for democratic reforms, an end to corruption, and the reinstitution of the four freedoms. The protests were led by the Beijing Workers Autonomous Federation BWAF, a labour union independent from Communist Party control, and the Beijing Students Autonomous Federation BSAF, a self-governing student organization, which together called for the advancement of democracy and the end of dictatorship. After dialogue between the protestors and the government broke down, the government declared martial law and 