BWR cutaway, source Wikicommons
A drop in pressure and loud noises were heard outside of Fukushima's nuclear reactor local morning time. Engineers worry the suppression chamber, the doughnut looking structure below the vertical reactor, was damaged. The chamber contains large amounts of water in the form of liquid and steam. Instruments recorded a drop from three times normal atmospheric pressure to ambient pressure over a short period of time.
BraveNewClimate has been following events closely and posting handy timelines, reactor-by-reactor status, and such. For whatever reason, the industries managing the crippled reactors seem to be having trouble conveying information to the outside world, including to the most senior levels of government:
Japan's prime minister was furious with the power firm at the centre of the nuclear crisis for taking so long to inform his office about a blast at a stricken reactor plant, demanding "What the hell is going on?"
What reasons would the industry have to spin, avoid, and evade? Lots and lots of reasons, according to this article from a former nuclear regulator (Or investigator? -- DS):
Last night, I heard CNN reporters repeat the official line that the tsunami disabled the pumps needed to cool the reactors, implying that water unexpectedly got into the diesel generators that run the pumps. ... That they didn't work in an emergency is like a fire department telling us they couldn't save a building because "it was on fire."
In the face of sketchy information and issues distributing what info does exist using Japan's earthquake battered phone/networks, Japanese and some Americans in the area are beginning to worry what little news they are getting is either heavily edited or subject to industry spin. No one wants to start a needless panic based on unfounded rumors. But this thing has been going on for five days now, and if anything it seems to be getting worse in some ways. So unless local media -- indeed the whole world -- and project managers and engineers actually on the site are given complete, unfettered access to one another, with no government minder or corporate spinmeister in between that information and the public, not only will people act on and report the rumors, cover up scandals and conspiracies theories will soon reign supreme.
See also Richard Cranium's diary.