The Yellow River is one of several rivers that are essential for China's existence. At the same time, however, it has been responsible for several deadly floods, including the only natural disasters in recorded history to have killed more than a million people. Among the deadliest were the 1332–33 flood during the Yuan dynasty, the 1887 flood during the Qing dynasty which killed anywhere from 900,000 to 2 million people, and a Republic of China era 1931 flood (part of a massive number of floods that year) that killed 1–4 million people.