Train 102 was assembled in the way Dutch trains often were in the autumn of 1918, stitched together from sections that had begun their day in different cities. The forward carriages came from Zwolle, the rear ones from Enschede; another joined the consist at Hilversum, making eleven in total. The departure from Amersfoort was 9:46, from Hilversum 10:10, and the timetable promised Amsterdam at 10:40. The passengers were ordinary: clerks heading to offices, families visiting relatives, commercial travelers with sample cases, soldiers in uniform during the last weeks of a war the Netherlands had managed to stay out of. Most of them were riding in wooden carriages of the kind that had been standard since the previous century, comfortable enough, but built of a material that splinters when iron pushes against it.

It had been a wet summer. The embankment leading up to the Merwedekanaal bridge had been soaking for weeks, and as the investigative commission under minister Cornelis Lely would later conclude, the railway dike was in poor repair before the rain ever began. The locomotive had reached the bridge when the ground under the rails simply liquefied for nearly a hundred meters behind it. The engine and tender, gripped by the bridge ironwork, twisted sideways. A luggage wagon came to rest against the bridgehead. The next three carriages slid down the slope behind, and the wooden bodies of those carriages, with passengers still inside, were crushed between the carriage in front and the postal carriage that ploughed in from behind. The carriages further back stayed mostly on the tracks. The disaster, as disasters often are, was concentrated in a small space.

Help came from improbable sources. A surgeon was riding on Train 102 and had survived. He began first aid in the wreckage almost immediately, joined by two doctors who ran in from Weesp, by four nuns from the town, by soldiers who happened to be in the neighborhood. None of the train crew were among the dead, and they worked alongside the rescuers. The station chief at Weesp sounded the alarm at 10:45. At 11:40 the first aid train rolled in from Naarden-Bussum. A Red Cross train followed. Two ships sailing the Merwedekanaal stopped and took on the wounded. By half past one a tug had cast off for Amsterdam with thirty-six injured aboard, and half an hour later another ship left with thirty-two bodies, arriving at the Wilhelmina Gasthuis at four in the afternoon. Among the dead was Henri Gorter from Zwolle, a Dutch cyclist and speed skater who built ice skates for a living. He died that evening at the Binnengasthuis hospital in Amsterdam.

Train traffic between Amsterdam and Amersfoort was rerouted through Breukelen and Utrecht. Commuters from the Gooi region were threaded through Naarden-Bussum, Hilversum, and Utrecht to reach Amsterdam. Six days after the disaster, trains ran again over a single track at five kilometers per hour. On 2 December, with bridge and dike repaired, both tracks were back in service. The dead were buried. The injured began the long convalescence that 1918 medicine could offer. Forty-one names entered Dutch railway history as the worst toll the country had yet seen on its tracks, and the Weesp disaster would hold that grim title for forty-four years, until two trains collided in fog at Harmelen in 1962 and killed ninety-three.

The Lely commission's finding was unsparing: the dike had been soaked by prolonged rainfall, and its condition before that rainfall had been poor. The conclusion changed how Dutch engineers thought about the relationship between soil mechanics, hydrology, and the iron lattice of a national rail network laid across reclaimed land. In a country where almost every embankment doubles as a barrier against water, the lesson was urgent and the lesson was permanent. The bridge over the Merwedekanaal still carries trains today; the canal is now part of the Amsterdam-Rhine Canal, widened and rerouted in the 1950s. Commuters cross the same low stretch of land where the ground gave way, four trains an hour between Amsterdam and Weesp, no longer in wooden carriages, no longer in fog about what their tracks are resting on.