The
1985 Mexico City earthquake struck in the early morning of 19 September at 7:17:50 am (CST) with a
moment magnitude of 8.0 and a
Mercalli intensity of IX (
Violent). The event caused serious damage to the
Greater Mexico City area and the deaths of at least 5,000 people. The sequence of events included a foreshock of magnitude 5.2 that occurred the prior May, the mainshock on 19 September, and two large aftershocks. The first of these occurred on 20 September with a magnitude of 7.5 and the second occurred seven months later on 30 April 1986 with a magnitude of 7.0. They were located off the coast along the
Middle America Trench, more than away, but the city suffered major damage due to its large magnitude and the ancient
lake bed that Mexico City sits on. The event caused between three and four billion USD in damage as 412 buildings collapsed and another 3,124 were seriously damaged in the city.