Police put the driver of a Spanish train under investigation on Thursday after at least 78 people died when it hit a sharp bend at speed, derailed and caught fire near the pilgrimage center of Santiago de Compostela, in one of Europe's worst rail disasters.
Dramatic video footage from a security camera outside the northwestern city showed the train, with 247 people on board, careering into a wall at the side of the track as carriages jack-knifed and the engine overturned.
One local official described the aftermath of the crash, on the eve of one of Europe's biggest Christian festivals in the ancient city, as like a scene from hell, with bodies strewn next to the tracks.
"We heard a massive noise and we went down the tracks. I helped get a few injured and bodies out of the train. I went into one of the cars but I'd rather not tell you what I saw there," Ricardo Martinez, a 47-year old baker from Santiago de Compostela, told Reuters.
The train driver was under formal police investigation, a spokeswoman for Galicia's Supreme Court told Reuters, without naming him. The train had two drivers and one was in hospital, the Galicia government said.
It was not immediately clear which driver was under investigation or in hospital. The train was operated by state-owned company Renfe.
Newspaper accounts cited witnesses as saying one driver, Francisco Jose Garzon, who had helped rescue victims, shouted into a phone: "I've derailed! What do I do?".
El Pais newspaper said one of the drivers told the railway station by radio after being trapped in his cabin that the train entered the bend at 190 kilometers per hour (120 mph), twice the permitted speed.
"We're only human! We're only human!" he told the station, the newspaper said, citing sources close to the investigation. "I hope there are no dead, because this will fall on my conscience."
Investigators were trying to urgently establish why the train was going so fast and why failsafe security devices to keep speed within permitted limits had not worked.
Bodies covered in blankets lay strewn around the train track next to overturned carriages after the impact as flames and smoke billowed from the wreckage and bloodied passengers staggered away.
Cranes were still pulling out mangled debris on Thursday morning, 12 hours after the crash. Emergency workers had stopped their search for survivors, the court spokeswoman said.
Firefighters called off a strike to help with the disaster, while hospital staff, many operating on reduced salaries because of spending cuts in recession-hit Spain, worked overtime to tend the injured.
The disaster happened at 8.41 p.m. (1841 GMT/ 2:41 p.m. EDT) on the eve of a major festival dedicated to St James, one of Jesus' 12 disciples, whose remains are said to rest in the city's centuries-old cathedral.
The apostle's shrine is the destination of the famous El Camino de Santiago pilgrimage across the Pyrenees, which has been followed by Christians since the Middle Ages.
The city's tourism board said all festivities, including the traditional High Mass at the cathedral, had been cancelled as the city went into mourning following the crash.
In total, 178 people were taken to hospital after the crash, a regional government spokeswoman said. Of those, 95 were still being treated, of which 36 including four children, were in serious condition, she said.
U.S. citizens were amongst the injured, the U.S. embassy said in a statement and at least one British citizen was wounded, the British embassy spokesman said. Several other nationalities were believed to be among the passengers.
One official source said speeding was a likely cause of the derailment, but the public works minister said it was too early to say exactly what had happened.
One of the train drivers had been sedated, said Juan Jesus Garcia, the secretary general of the Renfe train drivers union, adding he hoped to visit him on Thursday. He had been operating trains in the area for three years, Garcia said.
Neighbors ran to the site to help emergency workers tend to the wounded. Ana Taboada, a 29-year-old hospital worker, was one of the first on the scene.
"When the dust lifted I saw corpses. I didn't make it down to the track, because I was helping the passengers that were coming up the embankment," she told Reuters. "I saw a man trying to break a window with a stone to help those inside get out."
Prime Minister Mariano Rajoy, who was born in Santiago de Compostela, the capital of Galicia region, visited the site and the main hospital on Thursday. He declared three days of official national mourning for the victims of the disaster.
Passenger Ricardo Montesco told Cadena Ser radio station the train approached the curve at high speed, twisted and wagons piled up one on top of the other.
"A lot of people were squashed on the bottom. We tried to squeeze out of the bottom of the wagons to get out and we realized the train was burning. ... I was in the second wagon and there was fire. ... I saw corpses," he said.
Both Renfe and state-owned Adif, which is in charge of the tracks, had opened an investigation into the cause of the derailment, Renfe said.
The official source said no statement would be made regarding the cause until the black boxes of the train were examined, but said it was most likely an accident.
Clinics in Santiago de Compostela were overwhelmed with people flocking to give blood, while hotels organized free rooms for relatives. Madrid sent forensic scientists and hospital staff to the scene on special flights.
The eight-carriage train was travelling from Madrid to Ferrol on the Galician coast when it derailed, Renfe said in a statement. The train left Madrid on time and was travelling on schedule, a spokeswoman said.
The disaster stirred memories of a train bombing in Madrid in 2004, carried out by Islamist militants, that killed 191 people, although officials do not suspect an attack this time.
Spain is struggling to emerge from a long-running recession marked by government-driven austerity to bring its deeply indebted finances into order.
But Adif, the state railways infrastructure company, told Reuters no budget cuts had been implemented on maintenance of the line, which connects La Coruna, Santiago de Compostela and Ourense and was inaugurated in 2011.
It said more than 100 million euros a year were being spent on track maintenance in Spain.
Wednesday's derailment was one of the worst rail accidents in Europe over the past 25 years.