[Bring_Back_Shantz]

Originally Posted by D as in David

Yes, "cost" is likely the #1 reason why not. There are over 500 schools in Calgary and one airport (I'm not including YBW because AFAIK, there is not much in the way of passenger security measures). The cost of implementing even half the security measures of an international airport into all the schools in the city would be massive, IMO.

Also, pretty ineffective.
Airport security isn't designed to keep people from getting guns, or other things into an airport, it's designed to keep people from hiding those things.

Metal detectors don't stop anyone who intends to go through them and shoot up a place from doing so, it just means they have to start doing it a little sooner.