In May, 1865, suffering from work exhaustion and extreme anxiety over his not-so-clandestine relationship with his mistress, Ellen Ternan, Dickens took her and her mother on holiday to France. He was writing OUR MUTUAL FRIEND and--as he had done all his life--he took the manuscript on vacation with him and continued to work on the end of Book III and the opening of Book IV.
After a month abroad, the group decided to return home. They crossed on Thursday, 8 June 1865, and then on Friday afternoon, 9 June 1865, boarded the 2:36 train at Folkestone to take them up to London. The train, packed with Continental pleasure-seekers, was in this configuration: a steam locomotive, a tender hauler for coal and water, a brake van, one second-class carriage, seven first-class carriages, three more second-class carriages, and three more brake vans with guards who could signal to the engine up front with whistles.
At 3:13, just beyond the Headcorn Railway Station and before the train reached Staplehurst, Kent, the conductor spotted a man wildly waving a red flag. The train was running about 50 miles per hour. The conductor whistled for the brakes and threw the engine into reverse, but the train could not stop before it hit the Beult viaduct, where a length of track was undergoing maintenance and reconstruction of the timbers holding it up.
The viaduct was about 10 feet high and 21 feet long; the river underneath was almost dry. The locomotive, tender car, first brake car, and one second-class carriage made it over the viaduct before the bridge and tracks gave way. One first-class carriage remained hooked and dangling; the others and two second-class cars went into the river bed, a toppled and mangled mess. One second-class car car dangled from the other end and the remaining brake cars remained on the tracks. Ten people were killed; another forty to fifty were severely injured. Countless others, including Dickens himself, sustained minor injuries.
There were two causes of the accident: 1) the construction foreman had misread the train schedules for that Friday and thought he had more time and 2) the flag-waver was placed too close to the viaduct, only about 554 yards back, instead of the mandatory 1000 yards.
Dickens and party were in the dangling first-class cabin. He climbed out through a busted window, helped Ellen and her mother up the bank, and then took to moving the dead to a secure area and caring for the injured.
He found a man with a cracked skull, his brain hideously exposed. Dickens gave the man some brandy and laid him on the grass. The man said, "I am gone," and died in his arms. A bloody, mangled woman was propped against a tree; Dickens gave her brandy, but in a moment she too was dead. One young passenger later recalled "Charles Dickens, the very novelist" had cajoled him to free himself from a pile of twisted wreckage. Another passenger recalled how Dickens, with his hat full of water, was "running about with it and doing his best to revive and comfort every poor creature he met."
When the emergency train arrived from London to take away the survivors, Dickens climbed back into the precarious, dangling car of the wrecked train to retrieve the manuscript of OUR MUTUAL FRIEND from his satchel. Although he claims in the Postscript to the novel that he was in the process of writing chapter 2 of Book IV, "The Golden Dustman Rises A Little," we now know that he was just a page or two short of finishing chapter 4, "A Runaway Match." Look at the last paragraph of chapter 4. You'll see what happened after the wreck.
Dickens suffered a great deal of what we would now call "post-traumatic stress." He lost his voice for two weeks. He quit traveling by train for the rest of his life (that is, whenever he could escape the necessity). And he died five years to the day of the wreck. His son claimed at his eulogy that "he had never fully recovered."