Not good

The earthquake, tsunami and its after effects are terrible enough. Our thoughts are with the people of Japan (we have quite a few readers there). The US Red Cross has setup to take donations for relief work there if you are inclined to go that route. If you are in Japan, and have alternative suggestions as to how we all can help, please do post them.
One of the after effects of this event was a destabilization of a boiling water reactor. There are 4 reactors at this site. One of them lost control over the steam pressure venting, and it appears to have blown its top.

This ain’t my area, I am not a nuclear engineer. What I saw looks like an explosive letting of pressure, in a cylindrically symmetric form going upwards, followed by a secondary outward more symmetrical force. See at 0:19 into the video. That looks like something blasted upwards at very high speed (you can see the upward shock wave, its not spherical as an unconstrained explosion), then outwards at a lower speed.
From what we are hearing, no one really has a clue as to whats going on, whether or not there is a core or fuel melt in progress.
I am hopeful that this video is simply of a burst pipe going under terrific pressure, and not a containment vessel blowing its top off. Not that a burst pipe is a good thing, but it would be the least of all possible and likely evils. But I am not encouraged by what I’ve read (most of which is likely wrong anyway).
Drudgereport is indicating that other reactors on site are having issues as well. Apparently the fail safe designs, at least some aspects of them, have failed, if the reports are to be believed, in such a way as to prevent reasonable failure state safety.
As I said, this isn’t good. Not that an earthquake, tsunami and likely 10’s of thousands of injured or worse is … stuff like this reactor bit tends to have significant multiplicative factors of bad.