At least 23 people are dead after the collapse of a Mexico City metro train overpass.

The overpass collapsed onto a road in the borough of Tláhuac, per the Associated Press. According to current Mexico City Mayor Claudia Sheinbaum, a support beam gave way as the train passed over it, with footage and photos of the aftermath showing train cars dangling from the damaged overpass. 

While at least 23 people have been confirmed to have been killed, it’s believed the fact that the collapse occurred near a section of road with a concrete median strip ultimately lessened the amount of deaths.

An estimated 70 other people were injured, with many having been transported to a nearby hospital. Of the 49 people who were reported to have been hospitalized as of Tuesday morning, seven were said to be in serious condition.

Monday night’s collapse marked one of the deadliest such incidents in the subway system’s history. As of Tuesday morning, per the latest update from the city’s Emergency Management agency, first responders were still on the scene and local residents were being advised to avoid the area.

The deadly overpass collapse occurred on the newest of the city’s subway lines, which—as with the bulk of the city’s subway system—follows an underground path except in less crowded areas. 

Marcelo Ebrard, current Foreign Relations Secretary in Mexico, previously served as Mexico City’s mayor at the time this line was constructed. He has faced criticism for the line’s design, with some claiming it was poorly made.  

Back in March 2020, two trains collided at the Mexico City Metro’s Tacubaya station, ultimately killing one person and leaving dozens injured.