The Wanggongchang Explosion (Chinese: 王恭廠大爆炸), also known as the Great Tianqi Explosion (天啟大爆炸), Wanggongchang Calamity (王恭廠之變) or Beijing Explosive Incident in Late Ming (晚明北京爆炸事件), was a catastrophic explosion that occurred on May 30, 1626, during the late reign of Tianqi Emperor, at the heavily populated Ming China capital Beijing, and reportedly killed around 20,000 people. The epicenter was a major production center of gunpowder, but it is uncertain exactly what triggered the explosion.