I had training at work today. It is a yearly event we have done since the terrible incident at Columbine High School in April, 1999. Back then the standard thinking in incidents like that was to contain the area and wait until a special unit like SWAT arrived and took over. Unfortunately it can take quite a long time for them to arrive and during that time many people continue to be injured or killed.
Today our response is much different. In such an event we will not wait and the first three or four officers that arrive will go into the building and search for the assailants and stop the threat by what ever means are needed.
I am glad we do the training but I pray we never need to use it.