MEXICO CITY — Misplaced studs, obvious design flaws and faulty welds led to the collapse of the capital’s subway system last spring, killing 26 and injuring dozens, Mexico City’s attorney general said Thursday. by publishing the results of a month-long survey.
The findings, detailed at a press conference, align with several of the findings of a New York Times investigation, which found improper installation of the metal poles was at the heart of the May 3 fatal crash. .
The metal studs were key to the whole construction, creating a composite unity between the steel beams and the concrete slabs. Once the studs failed, the entire structure fatally weakened, ultimately leading to collapse.
The dowels “connecting the concrete slab to the metal beams were misplaced,” said Ulises Lara López, spokeswoman for the attorney general’s office. “In the sections where the concrete slabs were detached from the beams, all the studs were improperly installed in irregular patterns.”
Such fundamental flaws, Mr. Lara said, could not have been discovered by routine inspection or avoided through regular maintenance.
In releasing her office’s findings on Thursday, Attorney General Ernestina Godoy Ramos described the report as “a thorough and serious scientific investigation, conducted by experts.”
An independent report released earlier this year by Norwegian risk management firm DNV also found serious construction errors, including with the placement and welding of metal studs. The Mexico City government had engaged DNV to investigate the causes of the accident.
The subway crash sent political shock waves, involving some of Mexico’s most powerful people, including Foreign Minister Marcelo Ebrard, who was Mexico City’s mayor when the line was built.
Mr. Ebrard and the current mayor, Claudia Sheinbaum, are both expected to run for president in the 2024 election.
The section of the metro that collapsed was built by the Carso Group, a vast conglomerate owned by one of Mexico’s richest and most powerful men, Carlos Slim, a close ally of President Andrés Manuel López Obrador. (Mr. Slim was also a major shareholder in the New York Times Company.)
Ms Godoy said her office would pursue criminal charges against those found responsible for the collapse, although she did not identify any individuals. “Just as our mandate is justice, our priority has been and will continue to be victims,” she said.