At 1:14 p.m. on 19 September 2017, a magnitude 7.1 earthquake struck near Raboso in Puebla state, about 120 km south-east of Mexico City, at a depth of roughly 57 km. Unlike Mexico's giant coastal subduction earthquakes, this was an intraslab event — a rupture inside the Cocos Plate itself, well beneath the surface, rather than at the boundary where the plate dives under North America.
The quake killed an estimated 370 people, 228 of them in Mexico City alone, where dozens of buildings collapsed as the same soft lake-bed sediments that amplified the 1985 disaster trapped and magnified the shaking again. Among the worst tragedies was the collapse of the Enrique Rébsamen school in the capital, which killed 19 children and 7 adults and became a national symbol of the disaster.
The date drew immediate, eerie comparisons: the quake struck on the 32nd anniversary of the 1985 Mexico City earthquake, just hours after millions of residents had taken part in the annual nationwide earthquake drill that commemorates it. It also came only twelve days after a separate magnitude 8.2 earthquake off Chiapas — the strongest to hit Mexico in a century — which had already killed nearly 100 people.
NOAA's National Centers for Environmental Information (NCEI) lists the 2017 Puebla earthquake in its Significant Earthquake Database with a maximum Modified Mercalli intensity of VIII in Mexico City, despite the epicentre lying well outside the capital. Investigations afterward found several collapsed buildings had been altered or built in violation of the city's seismic code, prompting prosecutions and a renewed push to audit high-risk structures across Mexico City.