Forty years ago today, on September 19, 1985 (August 5, 1985 lunar calendar), a strong earthquake of magnitude 8.1 struck the bottom of the Pacific Ocean off the southwest coast of Mexico. 9.19 Mexico City Earthquake At 7:19 am on September 19, 1985, a strong earthquake of magnitude 8.1 struck the bottom of the Pacific Ocean off the southwest coast of Mexico, killing more than 7,000 people and injuring more than 10,000. The shock wave reached Mexico City in about 2 minutes. The earthquake destroyed 30% of the buildings in the city center in 90 seconds. The earthquake was the most powerful and most damaging earthquake in Mexico's history. A strong earthquake of magnitude 8.1 struck the bottom of the Pacific Ocean off the southwest coast of Mexico. After the 8.1 earthquake on the morning of September 19, 1985, a magnitude 6.5 earthquake occurred the next day, followed by 38 aftershocks of magnitude 5.5 to 3.8. In the earthquake, an area of 32 square kilometers was affected, 8,000 buildings were damaged to varying degrees, more than 7,000 people were killed, 11,000 were injured, more than 300,000 people were homeless, and economic losses amounted to 1.10 billion US dollars. September 19 has been called "the most tragic day in Mexico City". The worst damage was in the heart of the capital, which is home to the offices of important government agencies and private enterprises of the country. In this area, more than half of the people work there during the day and go home at night. When the earthquake struck, many people were not at work, so more casualties were avoided. But the political, cultural, press and communications, and other public facilities here were severely damaged, causing water and power outages, traffic and telecommunications disruptions, paralyzing the city of Mexico City and causing chaos throughout the city.