The express had been struggling since Astorga. Nine minutes were spent checking the brakes there, and one of its two locomotives had to be uncoupled due to a hot axle box. Despite obvious problems during the steep descent through Branuelas -- brakes grinding uselessly against the rails -- the decision was made to press on. By the time the train reached Albares, it could not stop. The station master at Albares grabbed his telephone and called ahead to Torre del Bierzo: the express had lost its brakes on the gradient. At Torre del Bierzo, the station master sprinted for his office. Workers threw railway sleepers across the tracks, a desperate improvisation to slow the runaway. It was not enough. The train roared through the station with its whistle screaming and brake shoes glowing, heading straight for Tunnel No. 20 just beyond the platform.

Inside the tunnel, a shunting engine and three carriages were already moving -- their crew had been warned about the runaway and was trying to clear the line. They nearly made it. The last two carriages were still inside when the express struck them at speed. The impact drove the passenger train's first six carriages into each other, and the wooden cars ignited instantly, their gas lighting systems feeding the flames. Then came the third train. A coal train with 27 loaded wagons was approaching Tunnel No. 20 from the opposite direction. The crash had severed the signaling cables, leaving the signals showing clear. The driver of the shunting engine -- somehow unhurt -- saw the coal train coming and ran toward it waving frantically. The coal train slowed but could not stop in time, plowing into the wreckage and killing the shunting engine's driver and four railwaymen aboard the coal wagons.

The fire inside Tunnel No. 20 burned for two days. Wooden carriages, coal, and the confined space of the tunnel created an inferno that rescue teams could not approach. When the flames finally died, the heat had made identification of most victims impossible. Many passengers had been traveling without tickets -- common practice in wartime Spain -- which meant no manifest existed to count them against. Survivors later said the train had been packed, many of them heading to the Christmas fair in the nearby town of Bembibre. The official RENFE investigation file was lost, whether by accident or design, and the true death toll remains disputed. The official figure of 78 was almost certainly too low; contemporary estimates ranged from 200 to 250. The most recent detailed study, published in 2019 by historian Vicente Fernandez Vazquez, places the number at no more than 100.

Spain in January 1944 was barely five years removed from the end of its Civil War. Franco's government controlled the press with strict censorship, and a catastrophic rail disaster involving a state-owned railway was precisely the kind of story that would not be permitted to reach the public. The accident received almost no coverage. No public inquiry followed. The file vanished. It was only many years later, after Spain's transition to democracy, that journalists and historians began to piece together what had happened in the tunnel that night. A documentary later revealed that the locomotive displayed at the Catalonia Museum as RENFE 151-3101 is actually the Norte 5100 "Santa-Fe" -- the very engine that hauled the doomed express into the mountain. Even the physical evidence had been quietly mislabeled.

Torre del Bierzo sits in the El Bierzo region of Leon province, where the railway threads through the Cantabrian Mountains on its way from the Castilian plateau to the Galician coast. The gradient that defeated the express's brakes -- a long, steep descent through a series of tunnels -- is a feature of the terrain itself, and similar challenges have caused disasters on mountain railways across Europe. Today, the village is quiet. The tunnel still exists, the tracks still carry trains, and the mountains still impose their demands on anything that passes through them. The disaster is remembered locally but remains largely unknown in the wider world, one of those tragedies that censorship buried so effectively that even the lifting of censorship could not fully resurrect it.