Fifteen people were killed after a funicular streetcar derailed and crashed in Lisbon, Portugal, authorities said Wednesday.
The cause of the crash remains unclear. Officials have not released the nationalities of those who were killed.
Lisbon Mayor Carlos Moedas said in a social media post that the city “is in mourning.”
“The Lisbon City Council decrees three days of Municipal Mourning for the victims of the tragic accident at the Glória Funicular,” Moedas said. “I extend my heartfelt condolences to all the families and friends of the victims. Lisbon is in mourning.”
Armando Franca / AP 
The crash took place on a popular streetcar line called the Elevador da Glória, a landmark located in central Lisbon and often visited by tourists. It opened in 1885.
Portuguese President Marcelo Rebelo de Sousa’s office said in a statement that the president “deeply regrets the accident” and expressed “his condolences and solidarity with the families affected by this tragedy.”
This is a developing story and will be updated.