From testimony given in March by David Helsel, the superintendent of
the Blue Mountain School District, in Pennsylvania, at a meeting of the
Pennsylvania House of Representatives education committee:
Our district has been training staff and students in an armed-intruder
defense plan. Every classroom has been equipped with a five-gallon
bucket full of river stone. If an armed intruder attempts to gain
entrance, they will face a classroom full of students armed with rocks.
And they will be stoned...
Obviously the teachers have pepper spray. The rocks are just for
students. We used to have them huddle underneath desks. We’ve learned
from Virginia Tech: the gentleman that did it went to a shooting range a
week before and put the targets on the ground because he knew students
were going to be under the desks...
From the October issue of
Harper's. There's a bit more at the link, and it has a better title ("Schoolhouse Rocks").