Nuclear officials in Japan thought the Fukushima reactors were safe from the biggest waves a quake could hurl at them—thanks to a decade-old, one-page memo from the plant operator, reports the AP. Granted, it’s a double-size page, but it gives few details to back its claim that no tsunami poses a threat to the plant. Regulators were fine with the single-page response to their earthquake and tsunami safety questions. “This is all we saw,” said one. “We did not look into the validity of the content.”
The document wasn’t updated once in nine years, even as earthquake science advanced—and last year, when TEPCO took another look at safety preparation, it was the most cursory of checks, and one that arrived at the same conclusion: The plant would stay dry no matter what. “There was an attitude of disrespecting nature,” says an expert. In the memo, TEPCO reasoned that the plant wouldn’t face a wave higher than 18.7 feet, from an earthquake no more powerful than an 8.6 magnitude; this year’s tsunami hit 46 feet after a 9.0-magnitude quake. The company's disaster plan wasn't too detailed, either.