Structural integrity of Fukashima reactor pressure containment vessels

[Mike_Yates]

I heard that the pressure containment vessels of the Fukashima nuclear power plant was destroyed in the hydrogen blasts. Is this really true?

Each reactor is protected by a massive steel and concrete containment structure. Allegedly this shielding was destroyed as well as the reactor itself in at least on of the reactor units.

http://modernsurvivalblog.com/wp-content/uploads/2011/03/general-electric-boiling-water-reactor-mark-I.jpg