NASHUA, N.H. (AP) — Three firefighters were injured when a natural gas leak caused an explosion and fire Monday at a New Hampshire mental health center, but the building’s occupants all evacuated safely. About 40 people were in the Greater Nashua Mental Health facility when someone called 911 to report an odor of gas, State Fire Marshall Sean Toomey said. Firefighters were still investigating when the explosion happened and part of the building began to collapse, said Nashua Fire Chief Steve Buxton. The three injured firefighters were taken to a hospital with non-life-threatening injuries. The incident prompted authorities to send an alert to nearby homes and businesses telling people to extinguish any burners or flames and to prepare to evacuate. Jesci Larochelle, a resident less than a half mile away, reported feeling her house shake from the explosion. Nashua is located in southern New Hampshire, about 45 miles north of Boston.

The blast appeared to have obliterated at least part of the building, with aerial footage showing flames and smoke billowing from the rubble. Wreckage was scattered in the parking lot, and the response was hampered by cold weather conditions. New Hampshire Governor Kelly Ayotte, a Nashua native, praised the efforts of firefighters and first responders. This incident follows recent tragedies linked to gas explosions, highlighting safety concerns as authorities investigate more thoroughly.