Joint Press Release on August 27th Alertus False Alarm at
Londonderry High School
9/4/2025
Dear Londonderry,
The purpose of the message is to follow up in more detail on the August 27th Alertus False
Alarm that occurred at Londonderry High School (LHS).
It is customary for our Emergency Operations Committee (a partnership of School
Administrators, the Londonderry Police Department, and the Londonderry Fire Department)
to debrief all incidents after they occur to learn from them and better prepare for the safety
of our students and staff in the future. From this process we want to highlight:
The importance of redundant communication systems between the School District and
Police Department. Within seconds of the water leak tripping one of our Alertus buttons at
LHS, school staff were able to identify it was a false alarm. Two phone calls from LHS went
directly to dispatch at the Londonderry Police Department within those first few minutes to
let them know it was a false alarm. While this communication was occurring, our School
Resource Officers also received direct communication from the school system through
shared radios and an Alertus App that administrators were using at the time. The LPD
dispatch also heard all communications through a shared radio. Within those first few
minutes both organizations understood and communicated clearly it was a false alarm at
LHS.
These multiple redundant communication systems keep our staff and students safe at all
times.
One School Resource Officer was on site to assist the school administrators returning the
school building back to normal functions that afternoon in the aftermath of the false alarm.
On the afternoon of August 27th
, the Alertus beacon at the Londonderry Police Department
did not trigger an alarm at dispatch while all the other beacons worked at Londonderry High
School. Yesterday afternoon we tested the beacon at the LPD from two separate schools,
and it did work successfully. Both IT Departments will continue to collaborate to determine
the nature of the malfunction on August 27th.
The strong partnership between the Londonderry Police Department, Londonderry Fire
Department, and the Londonderry School District kept all students and staff safe that
afternoon and will continue to do so in the future.
Chief of Police Kim Bernard
Superintendent of Schools Dan Black
During the Londonderry, NH School Board meeting on 9/2/2025, a concerned parent, John Grenon, addresses the board regarding a critical flaw in the school’s Alertus emergency system. He explains that during a recent accidental activation of an active shooter alert, law enforcement and fire departments were not notified or dispatched, despite the system going off and students sheltering in place. Grenon emphasizes that the system is not configured to directly connect to 911 services or local emergency responders, a departure from best practices and safety standards. He urges the board to immediately rectify this issue by integrating the system with emergency dispatch, stressing the potential for tragic consequences if the problem remains unaddressed.