A year ago, on 17 October, a GNER train travelling at 117mph was derailed at Hatfield and four men lost their lives.
The cause of the accident was quickly apparent. It was a broken rail which through a series of errors, had been left unrepaired even though its weakened state had first been revealed almost two years previously.
What no-one predicted was that a year later, the Transport Secretary, Stephen Byers, would be announcing in Parliament that Railtrack would be turned into a non-profit making trust and that, effectively, the whole industry would be restructured.
The two events are, of course, connected.
In the aftermath of the Hatfield disaster, Railtrack, shorn of engineering expertise because of the way that the industry had been privatised, panicked and imposed hundreds of unnecessary speed restrictions around the country.
This led to enormous compensation claims by the train operators and consequently losses of £534m for the previously profitable company last year.
Massive rerailing was carried out throughout the country, but despite tens of thousands of inspections and thousands of speed restrictions, no rail as bad as the one at Hatfield was discovered.
It had been a one-off, remaining unrepaired because of the lack of communication between Railtrack and its contractor - but Railtrack's panic had crippled the network.
West Coast costs
It was not only Hatfield that killed off Railtrack. The company might have survived, despite the huge cost, had it not also been running up enormous losses on its biggest project, the refurbishment of the West Coast Main Line between London, Birmingham, Manchester and Glasgow.
Estimates of the final bill have gone up from £2.4bn to a staggering £8bn and still rising.
Railtrack seems to be completely unable to keep down its costs and this is the other reason that prompted Stephen Byers to step in to force the company into administration 10 days ago.
But Hatfield was the catalyst for Railtrack's demise.
In terms of railway history, it will mark a turning point - but to what direction is completely unclear.
Future confusion
The statement by Mr Byers on Monday evening gave few clues as to what the railway will eventually look like.
All we know is that Railtrack will be turned into a non-profit making trust, and major new projects such as the West Coast will be carried out by other companies.
However, we have no idea on whether the whole franchise map will be redrawn, and whether companies will be encouraged to merge in order to simplify the structure of the railways.
So far Mr Byers seems to have a blank sheet called "the structure of the rail industry" but little idea of what will fill it.
Although the government talks of £30bn being committed to the industry over the next decade, most of that is already allocated and, in any case, much of it is subsidy which the railways have always received.
Staff lose money
So, while the future of the railways is debated, passengers will experience no change except that even investment schemes to which the rail companies are already committed could be delayed because of the uncertainty.
Already last week Railtrack's performance plummeted because of the loss of morale among staff, many of whom were shareholders who have lost money because of the company's plunge into administration.
In railway terms, Hatfield was a relatively minor accident with a low death toll, not more than many of those Saturday night drunken road crashes.
But its impact will be felt far beyond more serious disasters such as Ladbroke Grove and Clapham.
Christian Wolmar's book on rail privatisation, Broken Rails, is being published by Aurum Press on 17 October.