FORT DRUM, N.Y. -- More than 100 emergency response professionals from Fort Drum and the local community recently took part in a full-scale mass casualty exercise at Wheeler-Sack Army Airfield, where Soldiers enjoying a leisurely cookout by the river underwent a simulated brutal attack.

"Nobody likes to think about the potential for an active-shooter incident," said John Simard, installation exercise and plans officer. "But modern-day realities demand that law enforcement and emergency response personnel prepare for worst-case scenarios."

Thursday's worst-case scenario kicked off at 8:30 a.m. with a 911 call placed by Spc. Jason Babin, 3rd General Support Aviation Battalion, 10th Aviation Regiment, 10th Combat Aviation Brigade.

In the scenario, Babin and about a dozen of his buddies had been given the day off. They were barbecuing on the Black River when one of the Soldiers opens fire on everyone at the gathering.

The suspect then flees the scene, rushes through a stretch of woods and enters his barracks on the airfield before barricading himself inside with a hostage.

After the 911 call, Fort Drum police were the first on the scene. The simulated casualties -- many of them concealed by tall grass -- screamed from the ground while putting pressure on their gunshot wounds.

Police with tactical gear and gas masks approached cautiously, questioned the casualties and quickly determined the shooter likely was gone.

Quietly, emergency response personnel and vehicles followed law enforcement down the dusty road into the woods and converged on the carnage by the river.

Security at the scene was tight. A hasty triage was set up. Officials treated victims, collected critical information and directed casualties to vehicles bound for area hospitals.

In addition to 10th CAB role-players and personnel from a myriad of Fort Drum directorates, the exercise required the coordination of emergency response personnel from surrounding communities, including Samaritan Medical Center, Carthage Area Hospital and Jefferson County Office of Fire and Emergency Management.

"For a mass casualty exercise with so many twists and turns, the coordination between Fort Drum and emergency responders from off post is huge," Simard said. "We don't have a hospital on Fort Drum, so we really rely on the local community for that support."

Capt. Mike Brisson, an operations officer who served as the 10th CAB liaison during the exercise, also used the training event to observe the actions of his peers from the Evans Mills Volunteer Ambulance Squad, where he is both a paramedic and the president of the squad.

"On the Army side, these are my Soldiers," Brisson pointed out. "But it's good to be able to track how our emergency medical (personnel) are doing on the civilian side, too. I was curious how we would do integrating on an Army post."

Throughout the exercise, which was codenamed "Falcon Rescue," antiterrorism and force protection experts from Fort Drum injected dozens of plot twists to the scenario that further developed training realism and made law enforcement react quickly under pressure.

One such twist was a suspicious bag -- which contained bomb-making materials and an anarchist's cookbook -- that was dropped in an abandoned nearby structure. Another twist involved threatening phone calls coming in to local law enforcement, which generated intensive investigating and analysis that ultimately led officials to the source -- the barracks.

During the ensuing simulated hostage negotiations, officials discovered the subject was cooking homemade explosives in his room.

"This is a major twist to the exercise that caused a lot of folks to do some hard work," said Simard, noting that emergency responders did not know any details ahead of the training event. "The whole scenario was as realistic as possible with many moving pieces."

Brisson said from an incident command perspective, the exercise showed that leaders were successful at establishing a "unity of command," ensuring that emergency response personnel are clear about who is giving and taking orders.

"For a mass casualty incident of this magnitude, especially in this day and era of active shooters, I think everything has gone very well," he said.

The massive exercise led to longer lines at the airfield gate, additional security checks, road detours and traffic delays.

Last year's mass casualty training simulated the crash landing of a C-130 at Wheeler-Sack Army Airfield while the full-scale exercise in 2011 simulated a redeployment of Soldiers to Fort Drum from Afghanistan who were suffering from a highly infectious disease.

In addition to training local, state and federal emergency response personnel, this year's exercise served as a culminating event to wrap up Antiterrorism Awareness Month.

Simard called the force protection exercise an overall success. He said most agencies involved did not expect such a complicated and system-stressing scenario that required quick and sharp adjustments in judgment and responses.

"This year's mass casualty exercise at Fort Drum tested our community's coordinated emergency response to an active shooter," Simard said. "On and off post, every element of that official response performed with poise, skill and efficiency.

"I couldn't be prouder of the team of professionals we have here at Fort Drum and the surrounding communities," he added.