We've long assumed that the double decker disaster scenario of a massive earthquake and tsunami caused the Fukushima meltdown. Turns out, all it took was the former, which knocked out Fukushima's cooling in less than 10 minutes.
Records released by TEPCO from the day of the quake show that the plant began to plunge into crisis long before the tsunami even hit - severely overheating and quickening the subsequent meltdown. Of course, the damage from the tsunami didn't help. But this revelation means simply building protective sea walls won't keep Japan's other nuclear sites safe - just being in a quake-prone region is enough to cause disastrous damage. [New Scientist]