On February 4, 1975, at 19:36 CST, an earthquake of Ms 7.5 and intensity (MMI) IX hit the city of Haicheng, Liaoning, China. The successful early evacuation ordered by Chinese officials, based mainly on the pronounced foreshock sequence leading up to the earthquake, makes it a notable instance of earthquake prediction. The evacuation remains the only successful evacuation of a potentially affected population before an earthquake in history. The evacuation of the city prevented up to 150,000 deaths according to estimates, however, many died from fire and hypothermia in the subsequent days.
None of the precursors observed in this earthquake were observed in the 1976 Tangshan earthquake, which killed over 240,000 a year later.