Metal Detectors at schoold

A 5th grade child brought a bb gun to school and when school was over he got on the bus and then my grandson, who is in kindergarton got on and the other boy took out the gun and pointed it at my grandson's face and told him to put his hands up and pulled the trigger. It was not loaded thankfully but imagine if it was. The boy also stated he has a real gun at home. Now my grandson cries and begs to not go to school or be on the bus. A bb gun can kill or do serious damage. No child should not feel unsafe like this.