CHARLOTTE, N.C. -- Local emergency crews prepared for the worst-case scenario at a Charlotte high school Monday, testing their skills to make sure children are safe.

Crews turned Myers Park High School into a training site for three hours since students were out for a teacher workday. But about 400 student volunteers and the entire staff of Myers Park participated in the full-scale training drill.

Authorities pretended that shots had been fired and explosives detonated inside the school during the morning. The students and staff were evacuated and bussed to Cricket Arena to wait out the drama.

Helicopters, ambulances, police officer and firefighters took part in the practice, treating it like a real event complete with blocked off roads and called-in backup. Special Weapons and Tactics team members even searched the grounds for the mock gunmen who got inside the school.

Rescue crews even had to help some children pretending to be injured by gunfire.

Charlotte-Mecklenburg Schools officials said the district has never participated in a drill of this magnitude, but the life-like drill was a good way to test out its crisis plans.

"This is a wonderful opportunity to see exactly what works and what doesn't with our emergency plan," said Latarja Henry, spokesperson for CMS. "Plans are evolving so this gives us an opportunity to exercise it to see where our weaknesses and our strengths are."

CMS does emergency drills on regular basis, but none on this scale. Officials said they practice year-round. Every school has its own crisis plan that is evaluated each year.

Organizers of the drill said none of the weapons used in the drill were loaded and the mock explosives were also safe for participants.