EXPLAINER-Spain's high-speed train crash: what happened?

The last two out of eight carriages of ⁠the trademark-red Iryo train going from Malaga to Madrid derailed and hit the oncoming Alvia, causing the latter's first two carriages to derail and fall down an up to five-metre (16.4 feet) embankment. WHAT OFFICIALS ARE SAYING There was a 20-second interval between the first derailment and the impact, too short to activate the automatic braking system, according to Renfe chief Alvaro Fernandez Heredia, who also said human error was practically ruled out.

Sunday's train collision and derailment in southern Spain killed at least 39 people and left 122 injured, with officials highlighting the "strange" nature of the accident on a straight stretch of railway, while one theory pointed to a broken rail joint.

Here is what ‌we know so far: The accident happened at 7:45 p.m. (1845 GMT) near the town of Adamuz in the province of Cordoba, about 360 km (223 miles) south of the capital Madrid.

It involved two high-speed trains, one operated by the private consortium Iryo and the other by Alvia, run by Spain's public railway company Renfe. The last two out of eight carriages of ⁠the trademark-red Iryo train going from Malaga to Madrid derailed and hit the oncoming Alvia, causing the latter's first two carriages to derail and fall down an up to five-metre (16.4 feet) embankment.

WHAT OFFICIALS ARE SAYING There was a 20-second interval between the first derailment and the impact, too short to activate the automatic braking system, according to Renfe chief Alvaro Fernandez Heredia, who also said human error was practically ruled out. "It must have been some kind of failure in the rolling stock or ​the infrastructure, and that will take time" to investigate, he said.

Officials said the Alvia had apparently hit the derailed carriages or undercarriage debris of the Iryo. The 27-year-old driver of the Alvia train died in the crash, ‍Renfe said. The Iryo train was carrying around 300 people and had just left the historic city of Cordoba. Its speed at the moment of the accident was 110 kph, well below the maximum limit of 250 kph on that stretch.

The oncoming train, carrying 187 people, was travelling at a speed of 205 kph, Renfe said. The derailed Alvia carriages had 37 people in the first and 16 in the second. Most of the dead and injured came from the first two Alvia carriages.

Transport Minister Oscar Puente said that the Iryo was less than four years old and ⁠that the railway ‌track had been completely renovated last May with an investment ⁠of 700 million euros ($813.5 million). Iryo said the train was last inspected on January 15. Puente called the accident "tremendously strange" and said that had it not been for the oncoming train, the derailment would have likely caused no deaths.

FAULTY JOINT A POSSIBLE CAUSE? A source briefed on initial investigations told ‍Reuters experts had found a broken joint, which possibly created a gap between the rail sections and they believed it to be key to identifying the precise cause of the accident. The Transport Ministry only said the joint had broken as a result of the accident, ​but not before and would not provide further comment. The state-owned rail infrastructure administrator ADIF did not immediately respond to a request for comment on the claim. Jose Trigueros, president of the Association of Road Engineers, said ⁠his preliminary analysis suggested "failure of the undercarriage of the back units" of the Iryo train.

While he did not rule out a problem with the track, he said nightly inspections with tamping machines were meant to detect any rail fatigue, in which case the control centre automatically reduces the circulation speed. PREVIOUS PROBLEMS Train ⁠drivers' union SEMAF had warned ADIF in a letter last August of severe wear and tear to the railway track where the two trains collided, according to a copy of the letter seen by Reuters, saying potholes, bumps, and imbalances in overhead power lines were causing frequent breakdowns and damaging the trains.

ADIF did not immediately respond to a request for comment. According to a Reuters review of alerts on ADIF's X account, it has previously reported problems with infrastructure ⁠at Adamuz, from signal failures to issues with overhead power lines, that caused delays to high-speed trains between Madrid and Andalusia 10 times since 2022.

Iryo is a joint venture between Italian state railway operator Ferrovie dello Stato, airline ⁠Air Nostrum and Spanish infrastructure investment fund Globalvia. It began operating ‌in November 2022, starting with the Madrid-Barcelona route and expanding to other major cities. Iryo's ETR1000 train is manufactured by the partnership of Hitachi Rail-Bombardier in Europe for Ferrovie's unit Trenitalia. Renfe's Alvia trains are manufactured by local makers CAF and Talgo. Everest Insurance is the lead insurer for Renfe, and its cover provides passengers or their beneficiaries with compensation. Everest declined to ⁠comment on details of the policy period, deductible and triggers when approached by The Insurer.

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