What the students go through at school in the small town of West End is reminiscent of a fire drill.
In the loudspeaker system, the principal repeats the word "lockdown", after which the children take their positions.
Unlike a fire drill, however, the strategy is not to get out.
Instead, students barricade themselves behind locked classroom doors in hopes of not being detected.
The exercises are monitored by the police, who together with the school draw up a protocol of shortcomings that need to be remedied.
- We have been lucky because it did not happen here, but sometimes I think it makes people relax.
These exercises counteract it so that the children are ready, says police Ricky Gooch.
See how the exercise works and hear the students' thoughts in the clip.