VALENCIA, Spain, July 4 (UPI) -- A judge in Spain Tuesday began taking witness statements about a commuter train crash in Valencia that killed at least 41 people and injured 47 others.
The four-car train was traveling on Valencia's underground route and came off the rails between two stations Monday around 1 p.m.
Prime Minister Jose Luis Rodriguez Zapatero cut short a visit to India to travel back to Spain, and King Juan Carlos was also expected to travel to the city, the BBC reported.
A 3-day period of mourning was declared in the city.
Spain's EFE news agency reported the train had passed a safety inspection just a week earlier.
The national police service sent five special accident investigation officers from Madrid, and terrorism was quickly ruled out, the BBC said.
Local officials and emergency services said speeding, defective wheels or debris from a partial tunnel collapse were the most likely causes of the derailment.
