Apparently it is now the No. 3 reactor whose cooling system has failed and the initial reactor in question was cooled down with seawater.

And KM: Yeah, that's true, but hindsight, for all we know. wink
From what I know, this is a 40 year old plant that has managed to withstand an 8.9 quake and a tsunami now. Impressive actually.

BBC's take
Reuter's take.
Yes. I can haz a biz and site, no?