Are the nuclear reactors in Japan located underground?

Question:

http://www.nytimes.com/2011/03/22/world/…
The reason I ask is that in this photograph of Unit No. 3, there appears to be very little left but smoldering ruins. Is this part just the outer shell, and is the actual containment vessel underground?

Answer:

Here is an informative article describing the situation, it also has some diagrams:
http://bravenewclimate.com/2011/03/13/fu…

Note that the explosions were hydrogen gas explosions and were outside the containment vessel (unlike Chernobyl which had the hydrogen gas explosion inside the containment vessel because of poor reactor design). They blew away the outer shell of the building, but that's not part of the containment process.

Given that the forty year old power plants were first subject to an earthquake five times the force they were designed for and then they were hit with a tsunami, they're actually doing incredibly well. It says a lot for the safety of nuclear power.