The death toll in the crash of a Lisbon streetcar popular with tourists rose to 17 on Thursday after two people died from their injuries while receiving hospital care, an emergency services official said. The cause of the derailment remained unclear.

The dead were all adults, Margarida Castro Martins, head of Lisbon’s Civil Protection Agency, told reporters. She didn’t provide their names or nationalities, saying that their families would be informed first.

Another 21 people were injured in the crash on Wednesday, she said, adding that they were men and women between the ages of 24 and 65 as well as a 3-year-old child.

The injured included Portuguese people as well as two Germans, two Spaniards and one person each from France, Italy, Switzerland, Canada, Morocco, South Korea and Cape Verde, she said.

The range of nationalities reflected how big a draw the renowned 19th-century streetcar was for tourists who are packing the Portuguese capital during the summer season. Portugal observed a national day of mourning Thursday after the capital’s worst disaster in recent history.

Officials have declined to speculate on whether a faulty brake or a snapped cable may have prompted the descending streetcar to careen into a building where the road bends, and investigations were underway.

British tourist heard a ‘horrendous crash’

Felicity Ferriter, a 70-year-old British tourist, had just arrived with her husband at a hotel near the crash site and was unpacking her suitcase when she heard “a horrendous crash.”

“We heard it, we heard the bang,” she told The Associated Press outside her hotel.

The couple had seen the streetcar when they arrived and intended to ride on it the next day.

“It was to be one of the highlights of our holiday,” she said. “It could have been us.”

She said that the emergency response was “amazing.” Police and ambulances quickly “flooded in,” she said.

The yellow-and-white streetcar, known as Elevador da Gloria, was lying on its side on the narrow road that it travels on, its sides and top crumpled.

Italian tourist won’t ride one again

The electric streetcar, technically called a funicular, is harnessed by steel cables, with the descending car helping with its weight to pull up the other one. The car can carry more than 40 people, seated and standing. It is also commonly used by Lisbon residents.

Francesca di Bello, a 23-year-old tourist from Italy on vacation in Lisbon with her family, had been on the Elevador da Gloria a few hours before the derailment.

They walked by the cordoned-off crash site on Thursday, shocked by the crumpled wreckage. Asked if she would ride a funicular again in Portugal or elsewhere, Di Bello was emphatic. “Definitely not,” she said.

Though authorities gave no details about those killed, the transport workers’ trade union SITRA said that the streetcar’s brakeman, André Marques, was among the dead.

One of Lisbon’s big tourist draws

The 19th-century streetcar is one of Lisbon’s big tourist attractions and is usually packed with foreigners at this time of year for its short and picturesque trip up and down one of the city’s steep hills.

Teams of pathologists at the National Forensics Institute, reinforced by colleagues from three other Portuguese cities, worked through the night on autopsies, which were expected to be concluded early Thursday, officials said. The injured were admitted to several hospitals in the Lisbon region.

Detectives from Portugal’s judicial police force, which investigates serious incidents, photographed the rails and the wreckage on the deserted road.

“It hit the building with brutal force and fell apart like a cardboard box,” witness Teresa d’Avó told Portuguese television channel SIC. She described the streetcar as out of control and seeming to have no brakes, and said she watched passersby run into the middle of the nearby Avenida da Liberdade, or Freedom Avenue, the city’s main thoroughfare.

The crash occurred at the start of the evening rush hour, around 6 p.m. local time. Emergency officials said all victims were pulled out of the wreckage in just over two hours.

Service halted as inspections ordered

The service, inaugurated in 1885, goes up and down a few hundred meters of a hill on a curved, traffic-free road in tandem with one going the opposite way. It goes between between Restauradores Square and the Bairro Alto neighborhood renowned for its nightlife.

Lisbon’s City Council halted operations of three other famous funicular streetcars in the city while immediate inspections were carried out.

The Elevador da Gloria is classified as a national monument.

Lisbon hosted around 8.5 million tourists last year, and long lines of people typically form for the brief rides on the popular streetcar.

Carris, the company that operates the streetcar, said that scheduled maintenance had been carried out. It offered its deepest condolences to the victims and their families in a social media post, and promised that all due diligence would be taken in finding the causes.

President Marcelo Rebelo de Sousa offered his condolences to affected families, and Lisbon Mayor Carlos Moedas said the city was in mourning. “It’s a tragedy of the like we’ve never seen,” Moedas said.

“A tragic accident … caused the irreparable loss of human life, which left in mourning their families and dismayed the whole country,” the government said in a statement.

European Union flags at the European Parliament and European Commission in Brussels flew at half-staff. Multiple EU leaders expressed their condolences on social media.

(AP)