CNN  — 

An overpass carrying a subway train collapsed in Mexico City late Monday, killing at least 24 people, including children, according to local government officials.

At least 79 people have been hospitalized, officials added. Four bodies remain trapped inside the carriages that plummeted to the streets below.

The train was traveling on an elevated part of the city’s rapid transit system, on the newest Line 12 – also known as the Golden Line – when part of the overpass collapsed onto traffic below, Mexico’s Secretariat of Risk Management and Civil Protection said.

International engineering experts will be called in to help determine the cause of the collapse, which the country’s foreign minister, Marcelo Ebrard, called “the most terrible accident we’ve ever had in the public transport system.”

Mayor Claudia Sheinbaum told a news briefing on Tuesday that alongside an investigation by the attorney general, “we will hire an international company certified in metros and structural matters to conduct an external technical investigation.”

The Secretary of Foreign Affairs Marcelo Ebrard said he will fully cooperate with all investigations into Monday’s deadly subway overpass collapse in Mexico City. Ebrard, who served as mayor of Mexico City at the time the subway line was constructed, said: “I’m at the complete disposal of the relevant authorities, as I’ve always been, for everything that is needed.”

The collapse happened near Olivos Station, at 10:25 p.m. local time, according to Mexico City Interior Minister Alfonso Suarez Del Real.