There is no easy way to say it, but transportation safety is built upon the debris of past tragedies. The 21st-century traveller benefits from unprecedented levels of safety because of everything that has been deduced from previous disasters.
The so-called "black box" on your plane isn't there for the benefit of the current occupants. It is there to enable investigators to help future passengers and crew by eliminating yet more sources of risk. In the event of something going horribly wrong - or, as in the case of the recent British Airways jet at Heathrow, merely embarrassingly awry - the voices in the cockpit and the technical flight data can be analysed and fixes devised.
Much of the focus is on creating systems that can eliminate the risk posed by human fallibility. Sometimes it is possible to create a near-perfect safety culture, as the UK's aviation industry has demonstrated. The last fatal accident involving a British passenger jet took place in the 1980s. Since the Kegworth disaster in 1989, UK airlines have safely completed around 30 million flights.
Yet however smart the technology, however robust the procedures and however tough the regulators, there can still be unforeseen sets of circumstances that conspire to wreck lives.
When fatal accidents take place on the railways, there is quite correctly intense scrutiny from the travelling public. Passengers understandably expect hazards to be designed out.
Some may connect Wednesday night's disaster with the train crash in the southern suburbs of Paris earlier this month ago and conclude that rail travel is risky. For the second time in two weeks the formidable safety culture that characterises Europe's railways has fatally failed. Yet rail remains orders of magnitude safer than the roads. The death toll in Santiago de Compostela, appalling as it is, equates to the number of people who perish on the roads of Spain in the average fortnight.
Despite the tragedy, Spain will remain ahead of the rest of Europe in terms of its high-speed network. Until the 1990s, the country's railways were the slowest and most antiquated in western Europe - an Iberian cul de sac with railways of non-standard gauges trundling through difficult terrain. Over the past two decades, the country has invested in Europe's most modern and extensive network of high-speed trains, taking advantage of the tracts of emptiness to connect Madrid with Barcelona, Valencia and Seville at speeds close to 200mph.
Modern high-speed lines are statistically far safer than conventional tracks. But when significant numbers of people are moving at speed, on land or sea or in the air, the potential for large-scale loss of life can never be entirely eliminated. While families grieve, all that we can do is try to learn.