The disaster in Japan was huge enough and tragic enough that news outlets and officials have largely avoided the blame game in favor of emergency coverage and response. But it has started with a vengeance today, as a report surfaced overnight that found Tokyo Electric Power Co.'s own engineers had warned in 2007 that the Fukushima nuclear plant faced a 10 percent chance of being "test[ed] or overrun" by a tsunami in the next 50 years.

Despite the warning, Reuters reports, TEPCO did not make changes to the plant, and the Japanese government did not step in, preferring to leave safety regulation in the hands of the utility.

Among examples of the failed opportunities to prepare for disaster, Japanese nuclear regulators never demanded that Tokyo Electric reassess its fundamental assumptions about earthquake and tsunami risk for a nuclear plant built more than four decades ago. In the 1990s, officials urged but did not require that Tokyo Electric and other utilities shore up their system of plant monitoring in the event of a crisis, the record shows.

The Reuters report follows an Associated Press investigation published on Sunday which reported that TEPCO consistently downplayed the possibility of a tsunami at the Fukushima plant.

The scrutiny on planning at the nuclear plant comes as the mystery of TEPCO chief executive Masataka Shimizu has been located. A little over a day ago several news outlets published rumor-filled accounts that he had committed suicide, checked into a hospital or fled the country. The company has now confirmed that Shimizu has been hospitalized for "dizziness" and "high blood pressure.

The plant had walls high enough to protect it from a six-meter wave, but the tsunami that hit on March 11 measured 14 meters high. The backup generators were also susceptible to flooding. In addition, the 40-year-old No. 1 reactor, which exploded during the disaster, was scheduled to go out of commission in February. "But shutting down the reactor would have made it much more difficult for Japan to reach its target of deriving half of its total generation of electricity from nuclear power by 2030 — or almost double its share in 2007," Reuters reported.

The report goes on to detail the mistakes made in radiation readings over the weekend, and problems with ventilation systems and pressure gauges in a plant that never received the upgrades required for U.S. plants.

But U.S. plants are not immune to natural disasters, nor to the now erroneous-seeming judgment calls reported from Japan. The operator of California's Diablo Canyon is currently seeking extensions to its own 40-year operating licenses, even though, as the New York Times reported this week, a new fault line was found just a half a mile from the plant. The Times report touches on how U.S. plants are generally more secure than those in Japan, because of post-Sept. 11 upgrades, but it also points out that "the inherent problem, risk experts say, is that it is hard to determine the size of the worst natural hazard." Such as, say, a 14-meter tsunami.