Minor mistakes can be caused by carelessness or ignorance. Major disasters are almost always caused by inadequately designed systems. A rotten barrel is more likely to spoil the apples than the other way around. What about the Normal Disaster Theory? The sinking of the Titanic is a perfect example. The iceberg alone could not have sunk the Titanic and cost more than a thousand lives. The sinking was caused or made worse by more than a half dozen things that went wrong. Most of them point back to the belief that the Titanic was unsinkable. That belief started a series of events that made it a disaster waiting to happen.
~ Jerry Mills
Basic Reality (or "How Reality Really Works"), page American Action Repo