A fracture in a straight section of track occurred prior to the passage of a high-speed train that derailed, causing last Sunday's rail disaster in which 45 people died, an initial report has found.
A train run by private company Iryo derailed last Sunday and its rear carriages crossed onto the opposite track into the path of an oncoming train run by state-owned Renfe.
The CIAF rail investigation commission stated that both the front carriages of the Iryo train, which remained on the track, displayed notches in their wheels, a condition shared by three earlier trains that also traversed the track.
Investigators are focusing on a gap of nearly 40cm (15 inches) in the track as a critical factor in the crash.
Sunday's deadly collision took place at around 19:45 local time (18:45 GMT), approximately an hour after the Iryo train departed Málaga for Madrid.
The last three carriages of the train derailed and collided with the Huelva-bound Renfe train. Carriage six derailed due to a complete lack of continuity in the track, the preliminary report indicated.
Most casualties were in the front carriages of the state-operated train.
Earlier this week, Spanish Transport Minister Óscar Puente confirmed the findings of grooves on the wheels of the Iryo train's carriages that had safely passed the problematic area.
These grooves and the observed deformation of the track are consistent with prior damage, according to the CIAF report.
Three trains that passed over the broken track at various times prior to the accident also exhibited similar wheel notches, which could indicate the compatibility of damage.
The preliminary report, deemed a working hypothesis, requires further validation through detailed analyses.
Transport Minister Puente addressed reporters reiterating that definitive answers are pending, but if the fracture was indeed the cause, it likely occurred shortly before the derailment, making it difficult to detect.
This disaster represents Spain's most serious rail crash in over a decade, recalling the tragic 2013 derailment in Galicia that resulted in 80 fatalities and over 140 injuries.
