Story here.  Most of the stories on this and statements by officials seem to be playing up the police role in "rendering the weapons safe" and playing down the role of the heroic construction workers who subdued the attacker, first by hitting him with a truck (a vehicle can be used as a weapon as it was in this case). If the construction workers are mentioned, most of the stories seem to merely state they "tackled" the attacker.

Also note the suspect shot from outside the school fence, where an armed citizen legally carrying openly (an impossibility because of the ban on open carry in school zone) would have almost certainly deterred such an attack from even happening.