Run the troop you're dived into and the troop closest to the entrance to the corner. Then quickly dive into the troop farthest off in the room (You may need to Liberate to save him) and rush to behind the exposed root of the Babel. You won't be harmed very much there; the root acts as a kind of shield.
Then, fire away until backup arrives.
Failing that, how're your DNA Board and weapon customizations looking? --- "Be confident, think positive!"