The tragedy has sent shockwaves through the country, leaving families shattered and a community in mourning.
In the chaotic hours after the crash, family and friends made frantic appeals to locate the young girl’s parents, her 12-year-old brother Pepe, and her cousin Felix.
Hope flickered briefly as rumours spread that some of her relatives may have survived.
Mayor of Punta Umbria – near Huelva where the train was heading – Jose Carlos Hernandez Casino said the girl’s brother had been found alive in hospital.
It was later confirmed that the boy had died, along with both parents and the cousin.
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RAIL TRAGEDY
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DERAIL RIDDLE
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The couple have since been named as Jose Zamorano and shop owner Cristina Alvarez.
They leave behind their young daughter, who was taken into the care of the authorities in the immediate aftermath of the disaster.
Remarkably, the child is said to be practically unharmed.
She is now staying with her grandmother in a hotel in Cordoba after receiving three stitches to a head wound.
The family were travelling back from the Spanish capital after going to see the Lion King musical and watching Real Madrid beat Levante at the Santiago Bernabeu stadium.
Confirming the loss, Hernandez Casino wrote on social media: “I was reluctant to do so because it appealed to hope, but after confirming the discovery of the bodies of the Zamorano Alvarez family members who had been missing since last night as a result of train accident, I have declared three days of official mourning.
“We are experiencing these moments with deep sadness and pain.
“I share in the grief of all the families affected and convey to them the support, respect and solidarity of the entire Municipal Corporation and all citizens.
“During the three days of mourning, flags will fly at half-mast on municipal buildings and all planned institutional events will be suspended as a sign of respect and mourning.
Tributes have also poured in from those who knew the family personally.
An old friend wrote: “My deepest condolences to the family. May God given them comfort. This is a great loss for everyone.
“I was shocked by the news. Cristina was my classmate at school, and we spent many years together.”
At least 40 people were killed in crash, with more bodies expected to be found as heavy machinery works its way through the “mass of twisted iron”.
A source briefed on the initial probe into the cause of the deadly crash revealed a faulty joint had been found on the tracks.
Technicians found some wear on the join between sections of the rail – known as a fishplate – which had been there for some time.
Renfe president lvaro Fernndez told Spanish publicradioRNE both trains were travelling well under the speed limit of 250 kph (155 mph).
The first train to derail – an Iryo train – was travelling at about 130mph, while the second train – operated by Renfe – was travelling at roughly 127mph.
The president of state-funded firm Renfe said human error was ruled out.
The 27-year-old driver of the Renfe train – which was carrying nearly 200 passengers – was killed in the horror smash, El País newspaper reported.
It took the brunt of the impact and it’s understood most of the fatalities were of people in the front carriages of the Renfe locomotive.
The front two carriages plummeted down a 13-foot slope after impact.
Authorities are probing the exact circumstances of the crash, but SpanishTransportMinisterOscarPuente described the ordeal as “extremely strange”.
Puente added that all the railway experts he had consulted were “extremely baffled by the accident”.
Spain has Europe’s largest high-speed rail network with more than 1,800 miles of track connecting major cities across the country.
Spain’s worst train accident this century occurred in 2013, when 80 people died after a train derailed in the country’s northwest.