Groton — In the event of a mass casualty at the Naval Submarine Base, officials there would almost certainly rely on emergency service personnel in surrounding communities to help respond.

During such a chaotic situation, it's essential that differing groups of personnel are able to communicate and work together, and given that these incidents usually are over in a matter of minutes, a timely response is key, which requires a familiarization with the base.

So this year, sub base personnel, in the midst of their annual training exercise designed to test their response to a variety of threats, involved first responders from about seven different municipalities and even Lawrence + Memorial Hospital and Pequot Health Center, where about 20 "wounded" Naval Submarine School sailors were transported, in an active shooter drill Friday.

They were training for a situation that they hope doesn't happen, but for which, as recent events show, they must be prepared. Just two months ago, a 21-year-old Saudi Air Force trainee shot and killed three U.S. sailors at Naval Air Station Pensacola in Florida. Eight others were injured in the attack.

"We take a look at the broad (range of) threats that we might face, and we put our limited resources against addressing those that we think are most likely," said Capt. Todd Moore, commanding officer of the sub base.

In evaluating the success of the exercise, Moore said he was looking to see a "rapid and efficient response" by the base's security force and "efficient coordination with off-base resources."

"Probably the most important thing is good communication and that's why we are continually working to improve our ties with the local community and their response agencies, both technologically to get the right radio so we can all talk on the same frequency, and just getting to know these people and work with them. That goes so far to help out in an emergency," Moore said.

Those involved went through details large and small, such as which gate would offer quickest access to the scene, how they would prioritize injuries once on scene, and where ambulances would be staged. An evaluator said he was looking to see that there was "good integration" among police, fire and emergency service personnel.

There was an immediate debriefing following the exercise and, later on, those principally involved went into further detail on the response and areas for improvement.

The base's annual security drills, which are happening at naval installations across the country, continue through next week.

j.bergman@theday.com