Save A Lot complaint: Verbally abusive and violent cashier

As soon as I walked in the door I heard a cashier yelling at another co-worker Non-Stop. Apparently this cashier Helen was mad because the other co-worker handled a complaint that was made about Helen. Helena had just gotten into an argument with a customer and the customer complain to the shift leader. So Helen was planning, cursing and threatening they shift later as I stood in line I could not believe what I saw. It was Non-Stop and I have my children with me we thought this woman Helen the cashier was going to attack the shift leader.
The shift leader stay calm and ignored the threats as she was trying to work the register and help process customers. She was very professional.
Apparently Helen has no respect for anyone whether his customers or her shift leaders and she should be dealt with severely and written up at the very minimum. I almost called the police it was so bad

I was so shaken up by the whole situation as well as my children.

You need to do something swiftly and a serious manner that should never happen while a customer is trying to buy groceries with her children. I also felt bad for the shift leader. I would like for the district manager to call me cuz apparently the store manager here is not doing their job and holding cashiers accountable