The Wall That Failed

The tsunami struck the plant roughly 50 minutes after the earthquake. It overwhelmed the seawall, flooded the basement, and destroyed the backup diesel generators that kept the cooling systems running.

Without cooling, three reactor cores melted down over the following days, spreading radioactive contamination across the region. A 2008 internal study had warned that exactly this kind of wave was possible, but management set the warning aside as too costly to act on.