Initial reports from the U.S. Geological Survey (USGS) placed the magnitude of the quake at 8.1, but it was later revised upward to an 8.2, more powerful than the 1985 earthquake that devastated the country and left thousands dead.
According to Bloomberg:
The president said that 62 aftershocks followed the quake and it's possible that one as strong as 7.2 could strike in the next 24 hours. Peña Nieto also said that serious damage had been caused and that one million [residents] initially had been without power following the quake, but that electricity had been restored to 800,000 of them.
The Pacific Tsunami Warning Center said waves of one meter (3.3 feet) above the tide level were measured off Salina Cruz, Mexico. Smaller tsunami waves were observed on the coast or measured by ocean gauges in several other places. The center's forecast said Ecuador, El Salvador, and Guatemala could see waves of a meter or less. No threat was posed to Hawaii and the western and South Pacific.
The earthquake was sufficiently powerful to rock Mexico City—450 miles northwest from the epicenter—setting off alarms, toppling walls, and shattering windows. At least 26 people have reportedly been killed, but authorities say that number could rise.
The USGS pager system declared a red alert after the earthquake struck: "High casualties and extensive damage are probable and the disaster is likely widespread. Past red alerts have required a national or international response."
In a series of tweets following the quake, President Nieto expressed condolences to the families that lost loved ones and announced that schools would be closed for the day to assess the damage.
Videos on social media documented some of the effects of the quake across the country and the chaos that resulted:
This is from an office in Mexico City hit by the 8.4 earthquake.pic.twitter.com/PRkKUDsfEl
— Mikel Jollett (@Mikel_Jollett) September 8, 2017
WATCH: Dramatic video shows the moment a major 8.4-magnitude earthquake was felt at a mall in Chiapas pic.twitter.com/9agNE6F9TK
— BNO News (@BNONews) September 8, 2017
Así se vivió el sismo de esta noche en el Ángel de la Independencia pic.twitter.com/94e6wgjy5W
— BuzzFeed News México (@BuzzFeedNewsMex) September 8, 2017