You run through the concrete halls with your rifle in hand, suddenly, from down the hall you see a strange yellow gas make its way across the thin passageway, then, an officer bursts out the strange mist with a blood-stained cloth around his mouth, he can barely make out a few words before vomiting up blood and collapsing onto the floor..

"..GAS!.. GAS IN THE-.. GAS..!"

As he vomits his own blood chunks begin to spill out his mouth as if he was spitting up his organs, his whole body now stained in blood and vomit from the little food rations they had been consuming..