An overhead subway platform collapsed in Mexico City late Monday, sending metro cars plunging into the busy street below and killing at least 23 people including children, according to Mexican officials.

Seventy-nine people were rushed to hospitals, and at least seven were in serious condition and undergoing surgery, Mexico City authorities said. Mayor Claudia Sheinbaum told reporters Tuesday morning that rescue workers were still struggling to extract the bodies of four riders. Emergency personnel rescued one person alive from a car trapped on the road.

“There are unfortunately children among the dead,” Sheinbaum said. She did not provide further details.

The mayor said a support beam had given way as a train on the metro’s Line 12 was passing the Olivos station. She vowed a full investigation and said the city would hire a foreign firm to determine what had gone wrong. Opposition politicians and citizens accused authorities of neglect, noting that the metro line, inaugurated in 2012, had suffered from structural defects so severe that several stations were closed for months in 2014 for repairs. There were also reports of damage from a 7.1-magnitude earthquake in 2017.

Mexican President Andrés Manuel López Obrador expressed his condolences and support for Mexico City’s government.

“Every day we are going to be providing information about this unfortunate event,” he said at his morning news conference.

The overpass gave way in a giant cloud of gray dust at about 10:30 p.m. Monday as cars passed below. Two metro cars collapsed into a V shape.

Mexico City Mayor Claudia Sheinbaum said on May 4 that passengers trapped inside train carriages following a deadly railway accident have yet to be identified. (Reuters)

At least one vehicle was pinned under the rubble, photos showed. Police and firefighters cordoned off the area as family members converged and frantically sought information on relatives who might have been on the train.

A survivor identified only as Mariana told the newspaper El Universal that the train had been full, even though it was late. “There were a lot of people standing and sitting in the car, and when the metro fell, we went flying and hit the ceiling,” the 26-year-old said. After about 15 minutes, a passenger managed to break a window and those trapped inside escaped, she said.

A weeping woman at the site said she couldn’t find her 13-year-old son, Brandon Hernandez.

“I’m looking for my son,” she told TV Azteca. She said he had called her shortly before the accident from one of the subway cars as he traveled from the city center with a friend. “He was on the metro. I can’t find him anywhere,” cried the woman, who did not give her name.

The accident occurred near the Olivos station southeast of the city center. On Tuesday morning, hundreds of commuters lined up near the closed station to board buses.

Mexico City boasts the second-largest metro system in North America, after New York City’s subway. This was the second major accident for the system this year. In January, a fire broke out at a downtown substation, leaving one person dead and shutting down several major lines for weeks. Before the pandemic, around 4.6 million people traveled on the metro each day.

Line 12 extends from Mixcoac, in the west of the city, to Tláhuac, in the southeast. It was plagued by construction problems and allegations of corruption.

Mexican Foreign Minister Marcelo Ebrard, who was mayor of Mexico City when Line 12 was built, tweeted late Monday that the crash was a “terrible tragedy.”

“Of course, the causes should be investigated and the responsibilities for it defined,” he added.

Both Ebrard and Sheinbaum are considered possible successors to López Obrador, whose six-year-term is up in 2024.

Read more: