After the disaster, in anti-gore mode, select any level and shoot down one of the men. He may not disappear. If he does not, keep hitting his bag with a crowbar (if visible). He should appear have all his body parts dislocated. Note: This occasionally works better if you creep up behind him with a crowbar or enable the /notarget code. To get in anti gore-mode, go to the options menu and use the password protected area on the visuals.