I actually don't disagree with you - but I do not believe that's main issue.
Per TVC
I had mentioned this previously. What is the deadliest school attack in United States history? It was almost 100 years ago, in 1927.
How many firearms were used? None.
A 55 year old man lost a school board election and was angry at the world. He used dynamite and killed 38 children at school. He sat back and waited until rescuers rushed in to help, then he drove a pick up truck loaded with dynamite into the people and detonated that, killing and injuring more.
Counting the perpetrator who committed suicide in the explosion, there are 48 dead and 53 injured. It is 101 casualties at a school where no firearms were used.
That was in Bath, Michigan.