The problem here is that we have removed "personal responsibility" from the equation and we always go to the lowest common denominator.
Now, when a lunatic does something, our course of action is to remove all sharp items from everyone rather than just dealing with the lunatic.
I don't think the founders necessarily knew of these types of events, they did however disagree with the concept that everyone's rights must be abridged because one person does something stupid.
These events are used for control, period. Government doesn't care one bit about your dead child.