What a crock of cack.
When I was at school, or history classroom had old grenades, shells, helmets army atuff from WWI & WWII.
They never called in the bomb squad.
However I do remember a girl getting a 2 week suspension for theiving a pen from her friend as a joke, and a lad brought in a BB Gun and was shooting pupils, staff and passing cars and he got put on report (not suspended, or expelled) and it made the national papers