I am a long time resident of Japan, engaged in probabilistic risk assessment, or PRA. For almost 30 years I have helped engineers, scientists, and policy makers to understand the inherent risks of dangerous activities in areas such as aerospace, oil and gas, chemical weapon disposal, transportation, and, of course, nuclear power generation. I have always considered myself to be good at my work, delivering cogent insights to my clients and preparing them for accidents by focusing on the answers to three simple questions,

 "What can go wrong?",
 "How likely is it?", and 
 "What are the consequences?"

All of this changed on March 11, 2011, when the shortcomings of the risk profession hit me like the “A” train roaring across Brooklyn late on a Saturday night.

What did I learn? I learned three new answers to the three above questions:

1. The safer we make a technological system through analysis and testing, then when the system fails, the likelihood is that the failure will be catastrophic;
2. The current state of earthquake or tsunami (in fact any natural hazard) science is not yet at a level where we can predict when, where, or how severe the impact will be;
3. Risk is not just a numerical measure, but an understanding and continual conversation between technologists, policy makers, and ordinary people as to when “safe” is safe enough.

If my thoughts can reach the hearts and minds of one engineer, one policy maker, and especially the young people who will have to make the decisions of the future, then perhaps I can help create a safer world where people prepare for the unexpected.