As we predicted two days ago, the original "don't worry, everything's fine" picture presented by authorities in Japan is coming apart at the seams, along with the country's nuclear reactors.
From USA Today:
The quake and tsunami damaged three reactors at the Fukushima Dai-ichi nuclear plant, which lost their cooling functions necessary to keep the fuel rods functioning properly. At first the Unit 1 reactor was in trouble with an explosion destroying the walls of the room in which it is placed. Later, Unit 3 also began to experience problems.
Chief Cabinet Secretary Yukio Edano said operators released slightly radioactive air from Unit 3 Sunday, while injecting water into it as an effort to reduce pressure and temperature to save the reactor from a possible meltdown.
Still, a partial meltdown in the unit is "highly possible," he told reporters.
And the New York Times:
Japanese officials struggled on Sunday to contain a widening nuclear crisis in the aftermath of a devastating earthquake and tsunami, saying they presumed that partial meltdowns had occurred at two crippled reactors and that they were facing serious cooling problems at three more. The emergency appeared to be the worst involving a nuclear plant since the Chernobyl disaster 25 years ago. The developments at two separate nuclear plants prompted the evacuation of more than 200,000 people. [Meta-O note: this figure has since been upped to 250,000 at this hour.] The Japanese Nuclear and Industrial Safety Agency said that as many as 160 people may have been exposed to radiation around the plant, and Japanese news media said that three workers at the facility were suffering from full-on radiation sickness.