Also, parents of injured kids should sue the pants off parents of the kid who brought the gun.
They probably don’t have anything worth suing for. Nope, the parents of the injured kids will sue the school system. They have much deeper pockets.
Have you ever heard the phrase, "You can't get blood out of a turnip."?
The parents, I'm sure, are poor, probably living in government housing with no personal assets whatsoever.
I'm sure what will happen is an action will be filed against the school - they're the only ones with any money. And, I'm also sure that the school will settle. Welcome to tort laws in America.