The death toll in the collapse of Mexico City’s subway Line 12 rose to 25 on Tuesday night, while the number of injured people increased to 79, according to official data. Meanwhile, the city’s government announced that the Attorney General’s Office will open an investigation and that Norwegian company Det Norske Veritas will carry out an external evaluation.

Monday night, at 10:25 p.m., a beam supporting the elevated railway collapsed, causing two train cars to plummet. The site of the accident was very close to the Olivos station, in the Tláhuac municipality.

The accident caused immediate concern among Mexicans and attracted international attention. Foreign leaders, including U.S. Vice President Kamala Harris, showed their solidarity on social media.

Last night, a rail overpass collapsed in Mexico City. The United States offers our deepest condolences to the families and loved ones of those lost, and we wish a full and speedy recovery to those who are injured.

— Vice President Kamala Harris (@VP) May 4, 2021

Official reports estimate that over 100 people were aboard the two collapsed train cars. Most were returning home after a day at work. After the accident, the victims’ relatives embarked on a pilgrimage from hospital to hospital to locate their loved ones.

A more devastating pilgrimage took place at the Iztapalapa Mayor’s Office, where families identified the bodies of those who lost their lives in the accident. Meanwhile, social media users claimed that a lack of maintenance provoked the accident. To avoid speculation, the government announced that it would hire a team of Norwegian experts to study the case.

“This is a company that is unrelated to the operation of Line [12],” said Claudia Sheinbaum, Mexico City’s Mayor, at a press conference on May 4. “There are leased trains and several companies involved. So, to provide an expert opinion, we are choosing a company that has nothing to do with the subway’s operation.”

Visitamos nuevamente el lugar del incidente con ingenier@s, el secretario de obras y servicios, el director del instituto de seguridad de las construcciones, la directora del Metro. Ellos ayudarán a hacer una revisión general del elevado de línea 12 y otras líneas del metro. pic.twitter.com/XvC4zOQhaO

— Claudia Sheinbaum (@Claudiashein) May 5, 2021

Det Norske Veritas is one of the world’s leading risk management companies with experience in public transportation systems. It is also at the forefront of business-model certification based on international standards, according to its website.

Mexicans express their dismay

El tabasqueño Miguel Córdova narra con lágrimas la tragedia de la #Linea12 vive de pepenar botellas de plástico y duerme bajo el puente

“Se cimbró la banqueta… nos caímos, se vio cómo se vino hacia abajo el Metro en dos… se hundió”@RuidoEnLaRed

pic.twitter.com/lGIr1tlHQn

— Arturo Bolio (@ArturoBolio) May 5, 2021

“I have cried. Perhaps, some people there did not say goodbye to their families because of the government’s idiocy. They fill their pockets with money, buying cheap materials. Here are the consequences,” said Miguel Córdova, a resident of Mexico City.

In the last two years, Mexico City’s subway has experienced problems that raise questions on its operability, including a fire at the Control and Command Post, a train crash with no injuries, and constant delays.

In September, the subway will complete 52 years of operation since Line 1 entered service. The collapsed line is the most recently built, and construction finished in 2012.

The Olivos station accident recalls and Oct. 20, 1975, accident, when two trains of Line 2 collided head-on at Viaducto station, leaving 31 people dead and 79 injured.

Mexico City’s subway transports an average of 3.9 million passengers per day.

(Translated and edited by Gabriela Olmos. Edited by Kristen Butler)