MEXICOCITY -Preliminary findings of an independent investigation into the deadly collapse of a Mexico City metro rail line last month showed the accident was caused by a structural fault, a senior city official said on Wednesday.
Jesus Esteva, head of Mexico City’s public works department, said the probe by Norwegian firm DNV observed deficiencies in building materials used including bolts and deformation of structural supports in the part of the line that collapsed.
The report by DNV, an external auditor, refers to “six deficiencies in the construction process” that contributed to the accident.
“The aforementioned allows us to submit, on a preliminary basis, that the incident was sparked by a structural fault,” Esteva told a news conference held to present the initial findings that did not permit any questions from reporters.
Deficiencies identified included the welding of bolts and their attachment to girders, missing bolts on some girders, different types of concrete used, unfinished or poorly executed welding and the checks done on fillet welds, the city said.
The collapse, Mexico’s biggest train accident in years, killed 26 people and piled political pressure on close allies of President Andres Manuel Lopez Obrador, as well as Mexican billionaire Carlos Slim, Latin America’s richest man.
The incident has shone a spotlight on Slim’s construction business, Grupo Carso, which was involved in building the section of the metro that collapsed.
Grupo Carso did not immediately respond to a request for comment.
Mexico City’s Mayor, Claudia Sheinbaum, has faced awkward questions about the line’s maintenance along with Foreign Minister Marcelo Ebrard, who was the city’s mayor at the time of the inauguration of the line. Both are close allies of Lopez Obrador and seen as his possible replacements in 2024.
The metro, known as Line 12, was built by a consortium of Mexico’s ICA, Slim’s Grupo Carso and French trainmaker Alstom SA.
ICA and Alstom did not immediately respond to a request for comment.
Sheinbaum said DNV will oversee analysis of the principal fault, and that she would be in touch with the companies involved in the line later today.
Line 12 had repeatedly been reviewed and declared safe by officials since it opened in 2012, but problems led to partial shutdowns from 2014 to 2015 for repairs.