An investigation into the Mexico City metro disaster has revealed a series of construction flaws in the overpass that collapsed, killing 26 people and prompting angry demands for justice.
The initial report released on Wednesday by Norwegian engineering company DNV said a structural failure had caused the elevated section to give way on May 3, bringing a passenger train crashing down.
The preliminary findings, which were presented at a news conference by Mexico City authorities, identified a number of deficiencies in the construction process.
They include “unfinished and/or poorly executed welding,” insufficient bolts and the use of different types of concrete.
The experts also found deformations and fractures in the beams of the section that collapsed, injuring dozens of people and prompting accusations of negligence from devastated relatives.
The metro line, the city’s newest, has been plagued by problems since it was opened in 2012.DNV, which was hired by the authorities to investigate the causes, plans to deliver two more reports on July 14 and August 30, its Mexico director Eckhard Hinrichsen told the news conference.
The probe aims to establish if the design and materials were appropriate, if the construction was carried out in line with the design, and if the operation and repairs were factors in the crash.
Prosecutors are also investigating the disaster but have yet to publish their findings.
Mexico City Mayor Claudia Sheinbaum said she would put together a technical team to reinforce and repair the 24.5km (15-mile) line.
The furore over the crash has engulfed two of President Andres Manuel Lopez Obrador’s political proteges and leading contenders to be his left-wing party’s candidate in the 2024 presidential elections.