​​This information is preliminary and subject to change.

Release Date 5 March 2026

​On February 2, 2026, about 2:26 p.m., a natural gas–fueled explosion and fire occurred at the Greater Nashua Mental Health Center in Nashua, New Hampshire.[1]  The explosion injured three firefighters who were standing near the building at the time of the explosion. The gas distribution system was operated by Liberty Utilities, a subsidiary of Algonquin Power and Utilities Corporation, which provides gas service to the area. Visibility conditions at the time of the accident were daylight and clear, with no precipitation; the temperature was 33°F.

Before the accident, about 2:15 p.m., the Greater Nashua Mental Health Center reported a gas odor to 911. Employees and patients who were in the building were evacuated by two supervisors. The Nashua Fire Department notified Liberty Utilities of the gas leak about 2:22 p.m. while en route. Upon arrival about 2:24 p.m., firefighters entered the building through a staff‑only access point to conduct an interior sweep, obtain gas readings, and confirm that all occupants had evacuated.

The crew exited the structure and proceeded around the exterior, and when they reached the opposite side of the building, they encountered a damaged gas meter set releasing pressurized gas.[2] As the firefighters began to withdraw from the area, an explosion occurred in the building, injuring all three members of the crew who were standing near the building.

​Liberty Utilities technicians started arriving about 2:40 p.m., and they shut off natural gas at the service line curb valve about 3:00 p.m. The gas service line to the building was a 2-inch steel pipe operating at around 50 pounds per square inch, gauge; its maximum allowable operating pressure was 60 pounds per square inch, gauge.

​All aspects of the explosion remain under investigation while the National Transportation Safety Board determines the probable cause with the intent to issue safety recommendations to prevent similar events.

Parties to the investigation include:

• the Pipeline and Hazardous Materials Safety Administration; 
• New Hampshire Department of Energy, 
• New Hampshire State Fire Marshal; 
• Nashua Fire Rescue; 
• Nashua Police Department; 
• Nashua Fire Marshal’s Office; and 
• Liberty Utilities.