Source of mystery ‘booms’ nearly 20 miles away

Saturday afternoon disturbance may have been from AT4 training exercises at Fort Devens

NASHUA – Speculation ran rampant Saturday afternoon and evening as to the source of a series of loud “booms,” which rumbled across Greater Nashua and into parts of the two-state Merrimack Valley region.

A Londonderry resident, for instance, said the booms sounded “a bit like thunder, or the gate of a dump truck slamming shut,” in a social media post.

“Loud bang … thinking it’s the pond ice,” someone else wrote. “It sounded like thunder,” another Londonderry poster agreed.

And another contributor suggested, likely tongue-in-cheek, that “the loud booms are invisible alien spaceships over our heads.”

But a commenter named Norm had the most logical explanation, posting a reminder that “Fort Devens is live-firing this weekend.”

A Fort Devens law enforcement spokesman said Sunday that although he wasn’t on duty Saturday, he knows the weekend was “pretty active here … with training exercises.”

Indeed, an advisory posted on the Fort Devens Website lists two “live fire” training sessions, one on Friday involving mortars and one on Saturday, described as an AT4 live fire training session running from 9 a.m. to 10 p.m.

Nashua police and departments in several area towns began receiving calls between 3:30 and 4:30 p.m. Saturday from residents ranging from concerned to curious.

The bulk of the reports seemed to come from Nashua and neighboring towns, with somewhat fewer coming out of Manchester, officials said.

One social media user reported hearing the booms in Eliot, Maine, just over the New Hampshire border.

Nashua police issued a tweet at 4:30 p.m., stating that the department “received numerous reports of loud noise from multiple locations citywide,” but added they hadn’t been notified of any incidents.

Several people who posted to social media described the “booms” as quite loud, and a handful said they felt their houses shake.

Many of them expressed skepticism that the noises they heard could have come from Fort Devens, some 20 miles from


There were no reports of any damage in the region.

For more information on Fort Devens, including its training schedules, go to

Dean Shalhoup can be reached at 594-1256, or @Telegraph_DeanS.