As a parent that experienced this two years ago, I can confirm. Hearing about a threat at school, followed by shota.fired, and receiving a call from my fleeing child are those "life in slow motion" moments burned into my memory. It didn't alter the outcome, but it was very beneficial to everyone's mental state.
Disagree. Being able to communicate to your family or emergency services that a shooting is happening and/or that you are safe or not is invaluable.