It still doesn't matter. Not only nature had to "hit a nuclear plant the fifth largest earthquake ever recorded, then immediately follow that with a twenty foot high tsunami", that very earthquake and tsunami caused several orders of magnitude more deaths than the plant meltdown did (and don't forget there were several other nuclear plants that got shut down safely). It shouldn't really be brought up in the discussion of nuclear energy safety. It's not like Chernobyl, where someone screwed up and lots of people died. It's like noting that in 1945 someone driving through a village close to Hiroshima got blinded by the nuclear detonation and run over a pedestrian, and then using this to argue that cars should be banned.