A terrorist group have got hold of a nuke, the bad thing is, they have already launched it... The results were devistating... A whole city has been destroyed, killing millions of people. The terrorits hid in a bunker while the nuke hit, they have been down there for 3 months waiting for the after effects of the nuke to go away. It has created huge radiation clouds that are blocking out most of the light...

Counter terrorists: Get those bastards... They have wiped out millions of people! Kill them all and get the worker they found in the bunker...
Terrorists: Good job men! Now, get out of there safely, we cant afford to loose any of you, if the military find you, use the worker as a hostage...