There are several measures that you can expect professional responders to take when they arrive at the scene of a terrorist incident.

The first step that professional responders will take when they arrive at the scene is to conduct a thorough sizeup. They will follow steps that are very similar to those that CERTs take to determine:

What is going on

How bad the situation is and how much worse it could get

What measures can be taken to control the incident safely

What resources will be needed