A metro overpass has collapsed in Mexico City as a train was travelling over on Monday night.

One of the support beams on an elevated track gave way, which causes several train cars to plunge onto the road below.

The collapse took place at 10:30 p.m. local time. There were relatively few people aboard. The accident has left at least 79 injured and 24 dead, including children. The death toll could have been higher if it had occurred earlier in the day.

Most of the victims were likely working-class citizens on their way home from work.

The incident occurred in Line 12 between the Olivos and Tezonco stations. The line usually carries around 220,000 passengers a day. It runs east-west across densely populated low-income areas.

train collapse rescue workers

Pedro Pardo/AFP

The line was built by ICA, Carso and Alston consortium while Marcelo Ebrard was governor of the city. it was quickly inaugurated in 2012. Two years later, Senator Miguel Ángel Mancera closed 11 out of 20 stations temporarily due to infrastructure concerns.

An investigation made in 2017 suggested that the overpass had deteriorated tracks that needed immediate maintenance.

Mexico’s president, Andrés Manuel Lopez Obrador has stated that he will order an investigation on the incident.

before and after of overpass

Site of the incident vs. structure before the accident / BBC