Spain will observe three days of mourning for those lost in the high-speed train accident.

The Prime Minister of Spain, Pedro Sanchez, has declared three days of national mourning for those who lost their lives in a high-speed train accident that took the lives of at least 40 individuals.

Sanchez has also vowed to investigate the circumstances that led to the collision of the two high-speed trains in southern Spain, while rescue teams continue their efforts to sift through the debris.

Additionally, over 120 people sustained injuries when carriages from a train headed for Madrid derailed and crossed onto the adjacent tracks, colliding with an oncoming train in Adamuz on Sunday evening.

This incident marks the most catastrophic train crash the nation has experienced in over a decade.

Railway operator Adif reported that the incident occurred at 19:45 local time (18:45 GMT) on Sunday, approximately an hour after one train departed from Málaga en route to Madrid, derailing on a straight section near Córdoba.

According to Transport Minister Óscar Puente, the impact thrust the carriages of the second train into an embankment, with most casualties being in the front carriages of that train, which was heading south from Madrid to Huelva.

Rescue crews indicated that the mangled wreckage of the trains made it challenging to rescue individuals who were trapped inside the overturned carriages.

Sanchez visited the crash site along with senior officials on Monday afternoon.

He informed reporters, “This is a day of deep sorrow for everyone in Spain, for our entire nation.”

“We will uncover the truth, we will determine the answers, and once we know the details regarding the origin and cause of this tragedy, we will communicate it publicly with complete transparency and clarity.”

Puente mentioned that the investigation might take at least a month, describing the situation as “exceptionally unusual”.

However, Reuters cited an unnamed source familiar with initial findings indicating that experts discovered a defective joint on the tracks, leading to an enlarging gap between rail sections as trains passed over it. This joint is crucial for determining the cause of the incident.

The Spanish newspaper El País reported that it remains unclear whether this fault was a cause or a consequence of the collision.

According to rail authorities, there were 400 passengers and staff on the two trains. Emergency responders treated 122 individuals, with 41, including minors, still hospitalized. Out of those, 12 are in intensive care.

Puente stated that the number of fatalities “is not yet final”. Authorities are currently identifying the deceased.

The trains involved in the accident were Freccia 1000s, which can achieve speeds up to 400 km/h (250 mph), as per a spokesperson from the Italian railway company Ferrovie dello Stato.

Journalist Salvador Jimenez from RTVE, who was on one of the trains, described the impact as feeling like an “earthquake”.

“I was situated in the first carriage. There was a moment when it felt as if an earthquake occurred, and the train indeed derailed,” Jimenez recounted.

Images from the scene suggest that some train carriages had toppled onto their sides. Rescue personnel were visible navigating the train to extract individuals through the slanted train doors and windows.

A passenger bound for Madrid, named José, told public broadcaster Canal Sur: “There were people screaming, calling for doctors.”

All high-speed rail services between Madrid and the southern cities of Malaga, Cordoba, Sevilla, and Huelva have been suspended until Friday.

King Felipe VI and Queen Letizia expressed that they are closely monitoring the situation of the catastrophe “with significant concern” and extended their “deepest sympathies”.

The emergency management agency in Andalusia urged any survivors of the crash to reach out to their families or use social media to confirm their safety.

The Spanish Red Cross has mobilized emergency assistance to the site, and is also providing counseling to families in the vicinity.

Miguel Ángel Rodríguez from the Red Cross informed RNE radio: “Families are experiencing a great deal of anxiety due to the lack of information. These are very distressing times.”

In 2013, Spain encountered its most severe high-speed train derailment in Galicia, northwestern Spain, resulting in 80 fatalities and 140 injuries.

Spain’s high-speed rail system ranks as the second largest in the world, surpassed only by China, linking over 50 cities nationwide. According to Adif data, the Spanish rail network spans more than 4,000km (2,485 miles).