Officials said they believed the crash was an accident but declined to offer more details, saying an investigation was under way into the cause. There was no speculation by officials that it might be a possible act of terror, like the commuter train bombing attacks in Madrid in 2004 that killed 191 people.
The train, which belongs to the state-owned Renfe company, started from Madrid and was scheduled to end its journey at El Ferrol, about 95 kilometers (60 miles) north of Santiago de Compostela. Although it was not one of Spain's highest speed bullet trains called AVEs, it was a relatively luxurious version that uses the same kind of track as Spain's fastest expresses.
It was Spain's deadliest train accident since 1972, when an accident on a track heading to the southwestern city of Seville killed 77 people, the Europa Press news agency reported. A train traveling from Madrid to the Galicia region in 1944 crashed and killed 78 people. A subway crash in the southern city of Valencia killed 43 people in 2006 and was blamed on excessive speed.
King Juan Carlos and Prime Minister Mariano Rajoy both offered their condolences to the victims in Santiago de Compostela. Rajoy, who was born in the city, announced he would visit the crash site Thursday.
