The hammer story may be hypothetical, but here in UK in 1966 we had two "wacked-out" attacks on schoolchildren:

Dunblane (March)man armed with guns, teacher trying to protect children killed, 16 children killed
Wolverhampton (July)man armed with machete, teacher trying to protect children severely injured, three children injured, man fought off, no fatalities.

maybe guns don't kill people, but they make it a damn sight easier