As the world watches what looks to be a meltdown at Japan's Fukushima Daiichi nuclear facility, the Wall Street Journal reports the site's tested threshold for earthquakes was only 7.9—well below what transpired last week.

It's a development that's eerily reminiscent of the New Orleans levies, which were not designed to handle the massive force of a storm like Hurricane Katrina, and ultimately failed.

Such storms were considered rare, and according to the WSJ report, Japanese nuclear facility operator Tepco said something similar of quakes higher than 7.9. Mainly, that such quakes were not possible in the three tectonic plate region near their three nuclear plants.

Says the WSJ:

Tepco's last safety test of nuclear power plant Number 1—one that is currently in danger of meltdown—was done at a seismic magnitude the company considered the highest possible, but in fact turned out to be lower than Friday's quake. The information comes from the company's "Fukushima No. 1 and No. 2 Updated Safety Measures" documents written in Japanese in 2010 and 2009. The documents were reviewed by Dow Jones. The company said in the documents that 7.9 was the highest magnitude for which they tested the safety for their No. 1 and No. 2 nuclear power plants in Fukushima.

That said, this appears to be the "perfect quake" in terms of how it's knocked out these well-designed nuclear facilities. While the engineers did not prepare for a 7.9+ quake, they did install six backup generators and create a facility that initially survived a 9.0 magnitude quake. That is incredibly impressive engineering!

That the whole masterpiece was felled by a freakishly huge tsunami in the aftermath of the main quake is cruel, but that's how nature works sometimes, unfortunately.

At the moment, Japanese officials content the "situation is under control," and that radiation levels around the plant are low. [WSJ via Boing Boing, CNN]