Last weekend there were two oil spills. One took place in the Black Sea, where a Russian tanker split in two, releasing 2000 tonnes of oil. The other took place in the San Francisco Bay, where 58 000 gallons of oil were spilled after a cargo ship collided with a bridge.
Neither of these accidents should have happened. It has been reported that the oil tanker was a soviet era vessel designed for use on rivers which found itself facing eight meter high waves in the Black Sea. In San Franciso the LA times report that
"There were skilled enough individuals on board this ship," said Rear Adm. Craig Bone, the Coast Guard's top official in California. "They didn't carry out their missions correctly."
and there's the thing. In the first case safety rules either didn't exist or were ignored, in the second case it seems that something just went wrong.
This kind of thing happens all the time. In developed western nations we're used to most things working almost all the time, but no-one is really too surprised by events like this. In the developing world it's the other way round. For some reason though the notion that accidents will, and do happen often evades policy makers. They don't consider it when thinking about how to manage nuclear power stations, they don't consider it when looking at whether Genetically Modified Organisms can be released into the wild and they don't consider it when deciding whether or not it's a good idea to transport massive quantities of oil through pristine wilderness.
The moral of the story? If you do enough risky things sooner or later you'll get caught out. However good your processes and practices are.