When an earthquake of historic magnitude leveled the industrial city of Tangshan in the summer of 1976, killing more than a half-million people, China was already gripped by widespread social unrest. As Mao lay on his deathbed, the public mourned the death of popular premier Zhou Enlai. Anger toward the powerful Communist Party officials in the Gang of Four, which had tried to suppress grieving for Zhou, was already potent; when the government failed to respond swiftly to the Tangshan disaster, popular resistance to the Cultural Revolution reached a boiling point. In Heaven Cracks, Earth Shakes, acclaimed historian James Palmer tells the startling story of the most tumultuous year in modern Chinese history, when Mao perished, a city crumbled, and a new China was born.