Safety experts like to say that all accidents are preventable. This is of course, NONSENSE!
All accidents viewed in hindsight are preventable, but the very nature of those events we call “accidents” is that they are unforeseen in their specifics, but in general will always happen with absolute certainty — people will die in car wrecks, airplanes will crash, lightening will strike golfers, oil wells will blow-out, and nuclear plants will melt down. So long as we do these things, sooner or later, accidents will happen.
The business of estimating risk is often done in terms of probability —the lower the probability of an event occurring, the lower the risk. But this is not the whole story, and therein lies the rub. It is not just the likelihood of an event that should guide our decisions, but also the consequences of an accidental event, however unlikely.
In a typical car wreck, one or two people die and some repairable property is damaged.
In an airplane crash, a few hundred people die and some repairable property is damaged.
In an oil-well blowout 5000 feet below the surface of the ocean, a few people die, and the environment that sustains wildlife and the industry of a million or more people is despoiled, possibly irreparably.
In a nuclear power-plant accident, many people die and the affected environment is rendered uninhabitable for a thousand years of more, not to mention the similar long-term accident potential created by the storage of nuclear waste from plants that haven’t had an accident.
So the likelihood of an event occurring is of great interest, but the consequences of some events are of even greater importance than their likelihood. We must always ask what’s at stake. Some accidental events, no matter how unlikely, are not worth the risk.
