Spain is reeling from its deadliest train accident in more than a decade, with the death toll of a high-speed train collision rising to at least 40 people as emergency workers continue to search for victims and Spanish authorities promise an investigation into the accident’s causes, Aljazeera reported. 

The incident occurred when a train heading from Malaga to Madrid, with about 300 passengers on board, derailed near Cordoba in southern Spain at 7:45pm (18:45 GMT) on Sunday and collided with a train coming from the capital to Huelva, another southern city, carrying about 200 passengers.

“We are wondering what happened. Time and the work of the experts will provide the answer,” Prime Minister Pedro Sanchez said during a news conference. “We will uncover the truth with absolute transparency and make it known to the public.”