Three firefighters were injured, one seriously, and four people were unaccounted for after an explosion and fire at a commercial building on Amherst Street in Nashua.Alert issued after gas leak, explosion at 440 Amherst St. in Nashua.One firefighter seriously injured, two suffer injuries that are not life-threatening.Four people who may have been in building are still unaccounted for.Firefighters ordered out of building, but efforts to contain fire continue.People in area told to shut off burners, extinguish open flames.One of the firefighters suffered serious injuries, while the injuries to the other were not considered to be life-threatening. >> Raw aerial video: Firefighters respond to flames, explosion in NashuaFire officials said about 40 people were in the Greater Nashua Mental Health building at 440 Amherst St. when the gas leak was first reported at about 2:15 p.m. Fire Chief Steve Buxton said four people are still unaccounted for, but he believed officials would be able to make contact with them.>> See latest update from fire officials:An emergency alert was issued in New Hampshire about a potential gas leak after the fire and explosion.The emergency alert urged anyone in the area of 440 Amherst St. to extinguish burners or other flames and prepare to evacuate. People were told to stay away from the area.Nashua fire officials said the building was on fire when crews arrived. Some firefighters were trapped for a short time after a small explosion, but they were able to make it out of the building.People in the area reported hearing a loud boom.”Real loud. It shook a lot,” said witness William Closs, who was working in the area.When he saw the alert on his phone, he said he was already in the process of trying to evacuate the building he was in.”We were trying to figure out how to get people out, as it was the building right next to us,” Closs said.All firefighters were ordered to evacuate the building, but crews continued to fight the flames from outside. Heavy smoke could be seen pouring from the roof.Amherst Street was shut down between Somerset Parkway and Thornton Road. Closs said first responders helped evacuate his workplace. “They were quick, efficient, thorough,” he said.Closs said he had to leave his vehicle behind and was walking about a mile down the road to meet friends and family.Eversource said power was cut to about 10 customers in the area. The utility said power would be restored when it’s safe to do so.Officials at the nearby Nashua Airport said the fire had minimal impact on airport operations.This is a breaking news story. It will be updated as more information comes in.
Three firefighters were injured, one seriously, and four people were unaccounted for after an explosion and fire at a commercial building on Amherst Street in Nashua.
Alert issued after gas leak, explosion at 440 Amherst St. in Nashua.One firefighter seriously injured, two suffer injuries that are not life-threatening.Four people who may have been in building are still unaccounted for.Firefighters ordered out of building, but efforts to contain fire continue.People in area told to shut off burners, extinguish open flames.
One of the firefighters suffered serious injuries, while the injuries to the other were not considered to be life-threatening.
>> Raw aerial video: Firefighters respond to flames, explosion in Nashua
Fire officials said about 40 people were in the Greater Nashua Mental Health building at 440 Amherst St. when the gas leak was first reported at about 2:15 p.m. Fire Chief Steve Buxton said four people are still unaccounted for, but he believed officials would be able to make contact with them.
>> See latest update from fire officials:
An emergency alert was issued in New Hampshire about a potential gas leak after the fire and explosion.
The emergency alert urged anyone in the area of 440 Amherst St. to extinguish burners or other flames and prepare to evacuate. People were told to stay away from the area.

Hearst Owned
An alert was sent to phones in New Hampshire, warning people of the danger of a gas leak in Nashua.
Nashua fire officials said the building was on fire when crews arrived. Some firefighters were trapped for a short time after a small explosion, but they were able to make it out of the building.
People in the area reported hearing a loud boom.
“Real loud. It shook a lot,” said witness William Closs, who was working in the area.
When he saw the alert on his phone, he said he was already in the process of trying to evacuate the building he was in.
“We were trying to figure out how to get people out, as it was the building right next to us,” Closs said.
All firefighters were ordered to evacuate the building, but crews continued to fight the flames from outside. Heavy smoke could be seen pouring from the roof.
Amherst Street was shut down between Somerset Parkway and Thornton Road. Closs said first responders helped evacuate his workplace.
“They were quick, efficient, thorough,” he said.
Closs said he had to leave his vehicle behind and was walking about a mile down the road to meet friends and family.
Eversource said power was cut to about 10 customers in the area. The utility said power would be restored when it’s safe to do so.
Officials at the nearby Nashua Airport said the fire had minimal impact on airport operations.
This is a breaking news story. It will be updated as more information comes in.