An independent investigation, which analyzes the cause of the collapse of line 12 of the Mexico City metro on May 3, revealed that the origin of the accident was a “structural failure” of the construction. The incident left 26 fatalities.
The Norwegian firm DNV is behind the investigation that this Wednesday released more details about the incident on one of the Mexico City metro lines.
The company reported that they found structural flaws, deficiencies in the construction materials used, including the welding of the so-called Nelson bolts and their fixing in the beams and the deformation of the structural supports in the part of the line that collapsed.
As an external auditor, DNV referred in its preliminary expert report to “six deficiencies in the construction process” that contributed to the accident.
The investigation details that the fact is linked to the “porosity and lack of fusion in the bolt-girder joint”, to the “lack of Nelson bolts in the girders that make up the bridge assembly”, to the use of “different types of concrete on the tablet ”and to“ unfinished and / or poorly executed welds ”.
The content of the report was confirmed by Jesús Esteva, secretary of works of the mayor’s office of the Mexican capital, in charge of contracting DNV. “The incident was caused by a structural failure,” he said.
The results highlighted, on the contrary, that the line operated “in compliance with routine maintenance protocols.”
DNV’s director in Mexico, Eckhard Hinrichsen, participated in the presentation of the report. At the end of his reading, he said that he plans to deliver a second report on July 14 and a third document on August 30.
In parallel, the Mexican Prosecutor’s Office is conducting an investigation, but with no results yet published. The College of Civil Engineers of Mexico is also expected to present its own report this Thursday.
Tragedy in one of the largest transportation systems in Latin America
On the night of May 3, Mexicans witnessed one of the worst tragedies in their country’s public transportation system in recent years.
A beam from an elevated bridge on line 12 of the Mexico City subway, between Olivos and Tezonco stations, gave way and caused a train with passengers to crash, which was stranded in a “V” shape.
Nobody understood what was happening and in a few minutes images and videos of the car split in two began to be published on social networks.
Messages from relatives and friends of some of the victims were soon published in the media, all desperate because the person they knew did not respond to their calls.
Line 12 of the metro in Mexico City was built in 2012, during the mayoralty of the current chancellor, Marcelo Ebrard. Every day, about 220,000 people move on this line, which was also known for its constant noises and sharp curves. According to witnesses, the elevated bridge was left with visible cracks after the 2017 earthquake.
With Reuters, EFE and AFP