for more, i am joined by matthew bunn, an associate professor at harvard university's belfer center for science and international affairs, where he heads the school's main research group on nuclear policy. professor bunn, by taking natural disaster off the table and calling this "profoundly man made," what did the commission conclude that people did wrong? >> well, fundamentally, the issue was not being well enough prepared for the kind of natural disaster that did occur. certainly the earthquake and tsunami ultimately caused the health downs that happened but if they had been well enough prepared, if they had had, for example, the diesel generators protected from being flooded, if they had had water pumping into the cores of the reactors, if they had had a better emergency plan, these reactors might have survived. >> suarez: was there sufficient oversight to those plans? i mean, tsunamis often follow earthquakes, yet there was some surprise that the plants were destroyed by tsunamis. >> yes, unfortunately, both the company and the regulators had known years before that there was a subs