The possibility of a school shooting has become a serious concern at schools across the United States. Just days ago, a 15-year-old student in Jacksboro, Tenn., walked into his high school cafeteria and opened fire -- wounding two men and killing an assistant principal.
During the incident, the school went into "lockdown" mode -- where kids are required to go to designated classrooms and wait there until the emergency is over. In recent weeks, a San Diego school and one in a Washington suburb also went into lockdown after two scares over possible shooters.
"The issue of safety's a big issue," said Principal Lee Hamilton, of Shawnee High School in Shawnee, Okla. "I mean it's one of the primary issues of our school and every school that I know of."
Hamilton has an armed police officer on duty at the school and requires his students to perform regular lockdown drills.
But how well would their preparations work in a real emergency? With the help of ABC News safety consultant Bob Stuber and dozens of student volunteers, "Primetime" set out to see just how effective the lockdown method is.
First, "Primetime" installed cameras throughout Shawnee High -- in the classrooms, hallways and cafeteria.
The school staff and students were asked to behave just as they would if there were an armed intruder in the school. The students filed calmly to their designated classrooms where the teachers locked the doors, turned off the lights and waited for the all-clear signal.
To get an idea of how well the lockdown would work in a real-life situation, Stuber and his assistant Daniel Bauman acted as simulated gunmen the second time around -- without telling the students beforehand.
When the principal gave the alert the teachers again started moving the kids to the classrooms. This time, however, there was a surprise waiting for them, as the two pretend gunmen appeared out of the blue.
"You're dead," shouted Stuber, a former police officer and nationally renowned safety expert. "You're dead!"
Even though they knew it was only a drill, a sense of panic replaced the smiles that came with the first drill.
Some students thought quickly -- exiting the building through the nearest doors -- but most tried to follow their instructions and headed blindly for their designated classrooms.
Many of the students made it to their designated classrooms -- where again, the teachers locked the doors and turned out the lights.
Stuber says that could be a big mistake during a real crisis.
"The shooter's a student," Stuber said. "He already knows where they're going."
When the teacher went to check that the door was locked, Bauman threw the teacher to the ground and trapped the kids in the classroom like sitting ducks.
By the time the police officer arrived on the scene, the damage has been done.
Breaking the Rules
Stuber recommended simple steps, like fortifying locks on classroom doors and training kids to avoid classrooms with no windows.
"You want to get out of this thing alive," he said. "If you go into a classroom with no windows -- which some of these kids did -- you're in a dead end. That's very dangerous."
Stuber also says that in a life or death situation the rules go out the window and if you find yourself stuck in a room with no windows or ones that won't open, do whatever's necessary.
"In real life, normal life, the rule is you don't break things," he said. "But what they have to be taught is that in a situation like this, where it's life or death, there are no rules.
"You can use a computer, you can use whatever you can pick up. And they're thinking a computer costs money, you know, it's expensive. But I don't care. I would tell them, you can pick it up and use it."
According to Stuber, the key to survival is always to be alert, creative and aware of your environment.
Some might think a bathroom is good place to hide, but as the drill showed, that could be a potentially fatal mistake.
"It's not a great place to hide because there's usually no windows in here -- you're trapped," he said.
But, you can still survive if you keep your wits about you and make use of something handy -- even something as simple as liquid soap.
He says that by rubbing it on the floor in from of the bathroom door, you can create a slippery surface that the gunman will have difficulty navigating.
"That guy comes through the door, hits that stuff," he said. "I know it sounds like a Three Stooges movie, but that's exactly what it is. It works. He's going down, and you can go out."
But what if you're trapped in the open -- running down a hallway with a gunman chasing you? Again, Stuber says be prepared to make use of whatever is available in your environment.
Stuber shows that a fire extinguisher could be used to lay down a "curtain of concealment," giving you some much needed time to make a getaway.
One More Chance
Back in the classroom, the kids were given another chance to run the drill.
"You get to do what nobody else ever gets to do in this situation, you get to do it again. You get a second chance," he told them. "And this time, think about it. If there's something you could have done differently, don't be afraid to try it."
But again, the kids were thrown a curveball. This time, the main doors were sealed shut, denying the students an escape route.
When the alarm went off, Stuber and Bauman pursued the students again.
But this time the students thought on their feet instead of blindly going to their designated classrooms.
One group of kids -- seeing the front door blocked -- went out a side door, fleeing outside to safety. Two kids slipped into the principal's office and one student -- paying attention to which way the gunman is approaching -- fled in the opposite direction to safety.
Many students still went to their designated classrooms, but this time -- despite Stuber's best efforts to lure them out -- they stayed put and bought enough time for the police officer to take down both the gunmen.