Diana Acevedo, 16, a member of the Brentwood Legion Ambulance service’s mentorship program, volunteered as a deceased victim with a gunshot wound to the head. “Personally,” Acevedo said, “I was interested because I have seen what is going on in today’s world and I wanted to help first responders prepare for the worst.”

“They brought me to an ambulance and put a tourniquet on my leg and everything,” said Callie McLean (second from left), 14, a Petty Officer Third Class in the Southold NJROTC Unit. “If something like this were to happen, me and the others who participated would know, ‘OK, this is not a drill,’ and we’d know what to do in this sort of situation.”

A case of laceration wounds to be applied to "victims" by EMT's trained in moulage makeup.

Fake blood is applied to a volunteer on the school bleachers.

Students wait to get into character as first responders arrive at the mass casualty drill.

Emma Prindle, a Greenport high school student participating in an active shooter drill, observes applied moulage makeup and fake blood. Her father, Mike Prindle a fire fighter was on the scene participating in the drill.

A student is carried off on a spine board to be airlifted by an awaiting helicopter.

Volunteers in full character cried out in pain and aided in making the event authentic to first responders.

Dayanna Roldan (center) talking to Joseph McCarthy, Critical Incident Stress Management team leader. “If I have enough people to help me carry the patients that I'm dealing with, they’ll send a firefighter over to that person who is expiring or has expired and we’ll sit with them,” Bancroft explains. “We don't think anyone should ever have to pass on alone.”

Triage tags in green, yellow, red, and black were used during the drill to help emergency responders better prioritize victims. Here, a victim dressed up with a severe leg wound has been given a red tag, or "Priority 1," meaning he must be removed from the scene and given immediate medical attention.

“I see blood all over these stands. I’m not sure what’s going on. You better send the fire department and ambulance immediately. I don’t know. I saw some kid running, it sounded like firecrackers, and he fired some stuff into the woods and in the parking lot. It looks like he’s running toward the school," transcribed from a recording I made during the first call to dispatch by organizer Chief Chip Bancroft, founder of Firehouse Training Plus.

Firefighters extinguish a car fire, a diversion created by the school shooter to distract responders from the school.

Police Departments from Suffolk County and Southold participated in the drill, in which there were 62 simulated victims. Here, an officer enters an elementary-school classroom in pursuit of the “shooter.”

Emma Prindle, a Greenport high school student participating in an active shooter drill, observes applied moulage makeup and fake blood. Her father, Mike Prindle a fire fighter was on the scene participating in the drill.

"Less critical" student volunteers await triage.

First responders on the scene at Greenport High School on Long Island, NY.

Diana Acevedo, 16, a member of the Brentwood Legion Ambulance service’s mentorship program, volunteered as a deceased victim with a gunshot wound to the head.

A first responder tends to a victim.

Bloodied signage from the staged pep rally.

A victim is tended to beneath the school's bleachers, where a fall from the top seat was staged.

Police Departments from Suffolk County and Southold participated in the drill, in which there were 62 simulated victims. Here, an officer enters an elementary-school classroom in pursuit of the “shooter.”

Firefighters extinguish a car fire, a diversion created by the school shooter to distract responders from the school.

The Greenport drill was not imposed on the school’s staff or student body. It relied on students who volunteered to participate, and was held on a weekend rather than during school hours.