Mexico City Train Crash Updates as Bridge Collapse Threatens Rescue Efforts

At least 20 people have died - including a number of children - and around 70 were injured after an overpass in Mexico City partially collapsed onto the road on Monday night.

Line 12 of the Mexico City Metro plunged onto a stream of cars near Olivos station below the overpass, which stood around five meters (around 16 feet) above the road in the southside borough of Tlahuac.

Mexico City Mayor Claudia Sheinbaum said that "a support beam gave way," explaining it collapsed just as the train passed over it.

Rescue efforts were briefly stalled at midnight as the partially hanging train was reported to be "very weak," according to Sheinbaum, amid fears it could slip further into the road.

A crane was brought in to hold up a subway car left dangling on the collapsed portion of the overpass and allow emergency crew members to search the car.

The mayor said: "There are unfortunately children among the dead," without revealing how many, while seven victims were reported to be in "grave condition" and undergoing surgery.

A motorist was rescued alive from a car trapped under the rubble on the road, she added.

The city's Comprehensive Risk Management and Civil Protection Agency said 49 people have been hospitalized, 38 of whom have been identified.

Dozens of rescuers, including emergency medical crews and firefighters, were reported to be at the scene in search of survivors.

Line 12 travels on elevated structures through the outskirts of Mexico City, while running underground through more central areas of the city, which is home to around 9 million people.

It is among Mexico City's newest subway lines. It was built in 2012 while Mexican Foreign Relations Secretary Marcelo Ebrard was the city's mayor from 2006 to 2012.

Allegations around the line's poor design and construction came to light after Ebrard left office and in 2013, the line was partly closed so tracks could be repaired.

"What happened today in the Metro is a terrible tragedy. My solidarity with the victims and their families," Ebrard tweeted on Monday.

"Of course, causes must be investigated and responsibilities defined. I reiterate myself at the entire disposal of the authorities to contribute in whatever is necessary," he tweeted.

Mexico City Metro is one of the world's largest and busiest subway systems. It has seen at least two other serious accidents since it began operations nearly 50 years ago.

Last year in March, a train collision at Tacubaya station killed one passenger and injured 41 people. In 2015, 12 people were injured after a train that did not stop on time crashed into another at Oceania station.

05/04/21 5:00 a.m. ET: This article was updated after authorities said the number of deaths had risen to 20, to provide more details about the crash and about the history of the Mexico City Metro.