SANTIAGO DE COMPOSTELA, Spain -- A Spanish train that hurtled off the rails and smashed into a security wall as it rounded a bend was going so fast that carriages tumbled off the tracks like dominos, killing 80 people, according to eyewitness accounts and video footage obtained Thursday.
An Associated Press analysis of video images suggests that the train may have been traveling at twice the speed limit for that stretch of track.
Spain's government said two probes have been launched into the cause of Wednesday night's crash near this Christian festival city in northwest Spain. The regional government in Galicia confirmed that the train driver, hospitalized in Santiago de Compostela's main hospital with unspecified injuries, was being questioned as a possible suspect but that possible faults in safety equipment were also being investigated.
The Interior Ministry raised the death toll to 80 in what was Spain's deadliest train wreck in four decades. The Galician government said 94 remained hospitalized in six regional hospitals, 31 of them -- including four children -- in critical condition.
The U.S. State Department said one American was killed in the crash and five others were injured. It provided no other details.
Prime Minister Mariano Rajoy, a native of Santiago de Compostela, toured the crash scene alongside rescue workers and went to a nearby hospital to visit those wounded and their families.
"For a native of Santiago, like me, this is the saddest day," said Rajoy, who declared Spain would observe a three-day period of mourning. He said judicial authorities and the Public Works Ministry had launched parallel investigations into what caused the crash.
Eyewitness accounts backed by security-camera footage of the moment of disaster suggested that the eight-carriage train was going too fast as it tried to turn left underneath a road bridge. The train company Renfe said 218 passengers and five crew members were on board. Spanish officials said the speed limit on that section of track is 50 miles per hour.
An Associated Press estimate of the train's speed at the moment of impact using the time stamp of the video and the estimated distance between two pylons gives a range of 89-119 mph. Another estimate calculated on the basis of the typical distance between railroad ties gives a range of 96-112 mph.
The video footage, which the Spanish railway authority Adif said probably came from one of its cameras, shows the train carriages start to buckle soon into the turn.
Murray Hughes, consultant editor of Railway Gazette International, said it appeared that a diesel-powered unit behind the lead locomotive was the first to derail. The front engine itself quickly followed, violently tipping on to its right side as it crashed into a concrete security wall and bulldozed along the ground.
In the background, all the rear carriages could be seen starting to decouple and come off the tracks. The picture went blank as the engine appeared to crash directly into the camera.
After impact, witnesses said a fire engulfed passengers trapped in at least one carriage, most likely driven by ruptured tanks of diesel fuel carried in the forward engines.
"I saw the train coming out of the bend at great speed and then there was a big noise," one eyewitness who lives beside the train line, Consuelo Domingues, told The Associated Press. Then everybody tried to get out of the train."
Santiago officials had been preparing for the city's internationally celebrated Catholic festival Thursday but canceled it and took control of the city's main indoor sports arena to use as a makeshift morgue. There, relatives of the dead could be seen sobbing and embracing each other.
The Interior Ministry, responsible for law and order, ruled out terrorism as a cause.
It was Spain's deadliest train accident since 1972, when a train collided with a bus in southwest Spain, killing 86 people and injuring 112.
"July 24 will no longer be the eve of a day of celebration but rather one commemorating one of the saddest days in the history of Galicia," said Alberto Nunez Feijoo, regional president of Galicia. Santiago de Compostela is its capital.
The accident created a scene that was "Dante-esque," Feijoo said. He said Galicia would observe seven days of mourning.
Rescue workers spent the night searching through smashed carriages alongside the tracks.