A wall collapse at a residential construction site in Bedford Wednesday morning left five people injured, including one with life-threatening wounds, local authorities said.

Bedford Interim Fire Chief Paul Sheehan and Police Chief John Fisher said first responders received a call at 7:35 a.m. for a wall collapse and entrapment at 61 Dunster Road.

Local firefighters and police responded and found “multiple people trapped under a wall, with a bystander administering lifesaving first aid,” authorities said.

“Five people were extricated by first responders and transported to area hospitals for treatment. One person is believed to have life-threatening injuries. A Bedford firefighter was treated for injuries at the scene,” authorities said in a statement.

A Bedford building inspector “initially believed” the incident occurred due to improper construction techniques, authorities said.

“The federal Occupational Safety and Health Administration has arrived on the scene and will conduct a follow-up investigation, which will lead to a final determination of cause,” the statement said.

Bedford city records show the home at 61 Dunster road was built in 1971 and has seven rooms and 2 bathrooms. The city valued the home at $694,000 in 2023. It was last sold in April 2012 for $507,000, according to city records.