School crisis

Please answer the following

1. You are a responding psychologist/counselor to a school crisis in which several students were injured through a violent act committed by an offender who was taken into custody by the police. What is your first step when you arrive at the school?

2. After learning the details of the incident, what is next your next step? 

3. Is there anything else that needs to be done during this time?  

I need at least 3-5 sentences for each one.