According to reports, 23 people have died in Mexico City on Monday night after an overpass in the city’s rail system collapsed and sent a train plummeting down onto the busy road below. The tragic fall occurred on one of the new subway lines of Mexico City, Line 12, which operates underground but also moves to higher structures along the borders.

The Mexico City’s Risk Management and Civil Protection Agency took to Twitter to announce that 49 people had been injured during the collapse. The injured had been rushed to the hospital where 38 of them had been identified, the agency mentioned in the tweet.

Right after the rail overpass collapsed, Mexico’s mayor Claudia Sheinbaum arrived at the accident scene. She was heard telling the local press about how a motorist was taken out alive from a vehicle that was stuck in the middle of the road.

Sheinbaum was swamped with a number of questions from reporters who wanted to know the reason for the rail overpass collapse. In response, she said that a “support beam gave away,” claiming that the beam collapsed right when the train was passing through. Milenio TV released a set of clips and pictures of the accident site that show a train which has crashed onto the bustling road below and vehicles on the avenue that have been ruined by the rubble.

The incident prompted a response from Mexico’s Foreign Secretary, Marcelo Ebrard. He took to Twitter and shared his thoughts about the tragic incident and expressed solidarity for the victims and their families. Previously, Ebrard had served as the mayor of Mexico City from 2006 to 2012, and the metro Line 12 had been constructed during his tenure. Moreover, he further added that the reason for this collapse “must be investigated and responsibilities defined.”

It is important to note that Mexico City has one of the biggest metro rail systems in the world and yet, it has witnessed two major accidents before the one on Monday. According to the Associated Press, March of last year saw a terrible collision between two trains at Tacubaya station, which left one passenger dead and others severely injured. Another such collision occurred back in 2015 when a train did not stop and ended up crashing into another at Oceania Station, leaving 12 people wounded. The metro rail overpass collapse on Monday marks the third incident where the system has failed to prove itself reliable.