Looks like #3 is either bleeding off steam or something is still smoldering.
If that's in the correct order, that should be #1 off to the right there (with the weather cap missing). #2 (center right) looks pretty much untouched, but the weather shell is missing off the top there, too - not even the framework left. 3 and 4 look pretty dire. I bet the hydrogen cloud from 2 had drifted over away from 2 towards 3 and 4 before it ignited.
4 was powered down long before the earthquake arrived, so the reactor in that building wouldn't be why that'd happened. It wouldn't have been bleeding off steam and/or hydrogen. While 4's 'temporary storage pool' as it were is part of the containment building, it's relatively close to the surfaces of the 'cube' so it's not as well protected as the reactor proper. Someone posted this quick sketch of a GE Mk. 1 BWR/3 to Wikipedia which gives a good idea of the general placement of the spent fuel pool as well as the relative thicknesses of the walls and bulkheads.
* DW = Drywell
* WW = Wetwell
* SF = Spent fuel pool
The 30,000 fuel rods would not fit in that building's spent fuel pool (AFAIK). There are probably 30,000+ spent rods on the complex site, but they're not in reactor building 4.
Unit 3 is the only one we know of that has plutonium fuel; none of the others at the complex use MOX and wouldn't have any in their spent fuel pools. The (at the time) three operational reactors would have had empty spent fuel pools - those pools are there so you can reload the reactor and they are emptied when you have finished. Prior to restarting the reactor, you unload the fuel pool and take the spent rods to the safe long term storage facility elsewhere on the reactor reservation.
That building 4 must have gotten directly nailed by the overpressure (shock) wave and then hit again by air rushing back in to fill the vacuum. Looks like it might have been airburst (i.e., the H2 cloud body must have drifted right over it.) No wonder they're having problems with the pool on that one! Not seeing main containment breach levels of damage - but 4 is probably toast now too. Well, the building it's in, at least. The reactor core's probably just fine, but they're going to have to completely raze and rebuild that building before they can restart it.
Note that the auxiliary buildings around seem to be pretty much intact.
Edit: For size comparisons and clarification, here's some PWR fuel assemblies or bundles being inspected prior to irradiation. (Yes, it's safe for the technicians to do this with only that gear on.)
BWR fuel is the same except they have an external can or 'shell' around them. Technically, these are made of bundles of little bitty rods filled with
uranium pellets, but most people refer to each one of those bundle structures as a 'rod' - and I'm sure that the 'bundle' is what you were thinking they meant by a 'rod' in the media. Technically, it's correct, but saying it's '30,000 rods' is akin to me saying I have an enormous 933 engine in my Ford. Technically, yes, the 4.6 is 933 tablespoons, but it's deliberate verbal overinflation of the figures in a manner calculated to bring about a reaction by converting to a unit that people aren't thinking of.
You're not going to have 30,000 bundles in a reactor's transient spent fuel pool. Aside from not physically fitting, nobody'd be that dumb.
BWR bundles each contain about 91-96 rods, with between 368 to 800 bundles being used in each reactor depending on size with the larger and newer reactors using more. The BWR/3 is on the smaller end of that size scale, I'm guessing it's about 400 or so. Which explains where someone got the '30,000 RODZ OF DEATH' number. Please note the uranium pellet picture I linked above for the size of each pellet and the resulting diameter of the rod they live in. (They're single stacked.)