By Jim Garamone American Forces Press Service   GREAT LAKES NAVAL TRAINING CENTER, Ill. -- It's a sound all sailors recognize: a loud insistent gong sounding over the ship PA system. Then, "General quarters. General quarters. All hands man your battle stations." Navy recruits struggle to pull one of their wounded team member through a barbed wire obstacle as part of the Mass Casualty exercise at Great Lakes Naval Training Center. MSgt Brian Nickey, USAF The sound causes sailors' adrenalin to flow as they switch into combat mode. The call to general quarters means they drop whatever they're doing, don their battle gear and sprint for their battle stations. Seconds count, and performing tasks the right way during moments of absolute chaos can mean the difference between safety and swimming. Because naval warfare is serious business, training specialists here felt recruits needed exercises that were as real as they could possibly be. From this desire grew Battle Stations, the culminating event of the Navy's basic training. "We don't shoot anyone, but we try to make it as realistic as we can," said Petty Officer 1st Class Jeff Luce, a Battle Station specialist. The event begins at about 10 p.m. on the last week of basic training. In the course of the next 12 hours, sleep-deprived recruits must handle 12 different scenarios. During a mass-casualty exercise, for example, recruits enter a pitch-black room. Suddenly, all hell breaks loose. Lights flash and machine-gun chatter splits the air. Explosions go off. A recruit is declared wounded, and his teammates must put him on a litter and carry him to safety. Navy recruits push, pull and lift their wounded team member under and over many obstacles during the Mass Casualty exercise at Great Lakes Naval Training Center. MSgt Brian Nickey, USAF The team pushes and pulls the litter along passageways, under decks and through barbed wire. All the while, the only light recruits have to work by is strobe-like "explosions" in the room. After 10 minutes the team converges in a small area under the deck with another team coming from the opposite direction. Confusion reigns. Sailors yell over the explosions trying to create order from chaos. Finally, the sound system cuts out and the lights go back on. Sweat-drenched recruits try to figure out what happened. A facilitator critiques them and leads them to their next stop in Battle Stations.