MEXICO CITY, May 4 — A full investigation will be carried out into the causes of a overpass collapse that killed at least 23 people when one of Mexico City’s iconic orange metro trains plunged onto a busy road below, the city’s mayor Claudia Sheinbaum said today.

Two train carriages precariously hung from the damaged overpass after the accident late on Monday, and rescue efforts were suspended with authorities worried that more train parts and debris could slam down onto the road.

Speaking alongside Sheinbaum and other senior officials at a news conference, Mexican President Andres Manuel Lopez Obrador said that the investigation should be done quickly and nothing hidden from the Mexican people.

Foreign Minister Marcelo Ebrard, who was city mayor when the overpass was built, said it was the most "terrible” accident to have hit the local transport system, and that he was ready to cooperate with authorities in the investigation.

Sheinbaum said it was too soon to say who was responsible for what happened. — Reuters