Cary Grove Grade School to Simulate Mass Murder in Front of Students as Training Exercise
See the CBS Story
And some commentary from Popehat:
The simulation will take approximately 15-20 minutes, during which time teachers will secure their rooms, draw curtains, and keep their students from traveling throughout the building. Please note that we will be firing blanks in the hallway in an effort to provide our teachers and students some familiarity with the sound of gunfire. Our school resource officer and other members of the Cary Police Department will assist us in sweeping the building to ensure that all students are in a secure location during the drill. At the conclusion of the drill, we will take some time to process what occurred and then we will return to our normal classroom routine.