On 3 May 2021, at 22:22 CDT (UTC−5), an overpass carrying Line 12 of the Mexico City Metro collapsed beneath a passing train in the borough of Tláhuac. The overpass and the last two cars of the train fell onto Tláhuac Avenue near Olivos station, killing 26 people and injuring 98 others. It was the Metro's deadliest accident in almost fifty years.
https://www.nytimes.com/es/interactive/2021/06/12/espanol/america-latina/metro-ciudad-de-mexico.html
Until this note, Mexico City and the Sistema de Transporte Colectivo Metro authorities haven't revealed the date of reopening yet.