By Stephen Zogopoulos, USNN World News
Nashua, New Hampshire – February 2, 2026
A gas explosion rocked the Greater Nashua Mental Health building at 440 Amherst Street on Monday afternoon, igniting a massive multi-alarm fire that injured three firefighters and prompted emergency alerts across southern New Hampshire. The incident, reported shortly after 2:30 p.m., escalated quickly into a three-alarm response, with crews battling a gas-fed blaze in the 100×150-foot, two-and-a-half-story brick commercial structure.
Witnesses described hearing loud booms that shook nearby buildings, with heavy smoke and flames visible from the roof. “Real loud. It shook a lot,” said William Closs, who was working in the vicinity and received an alert on his phone urging evacuation. Aerial footage captured plumes of gray and black smoke billowing from the compromised building, which appeared heavily damaged with parts of the roof collapsed.
Nashua Fire Department officials arrived to find a gas-fed fire following the initial leak report. Some firefighters were briefly trapped after a small secondary explosion but managed to escape. One firefighter sustained serious injuries, while the other two suffered non-life-threatening wounds; all were transported to local hospitals. Due to the building’s severe structural compromise, crews shifted to defensive operations, fighting the fire from outside.
The Nashua Office of Emergency Management issued a shelter-in-place alert for residents near 440 Amherst Street, advising them to extinguish any burners or open flames and prepare for possible evacuation due to the ongoing gas leak. Amherst Street was closed between Somerset Parkway and Thornton Road, with officials urging the public to avoid the area near the old Building 19 property. Eversource reported cutting power to about 10 customers in the vicinity, with restoration pending safety clearance.
Neighboring departments, including Merrimack Fire, assisted in the response, highlighting the incident as a “commercial building fire with a natural gas explosion.” No civilian injuries were immediately reported, and the cause of the gas leak remains under investigation. Updates will be provided as more information becomes available.
