Level 6, how do I get into the armoury ?

[imported_blueberry]

I am on second floor and I kill all the guys in the armoury, but I cant get into it, I can look down into it but can't get in. I then from this position crawl through a shaft into the power room. How can I get into the armoury ? I know its on the first floor but i've swept that and nothing.

THanks.