LYNNFIELD — The Lynnfield Fire Department responded to a two-alarm fire at a single-family residence located at 105 Summer St. Wednesday night at approximately 10 p.m.

An off-duty Lynnfield Police officer, while driving home, observed the home on fire. He immediately notified the public safety dispatcher and attempted to determine if there were any occupants inside the home.

Upon arrival, first-due fire companies encountered heavy smoke and fire conditions coming from the right side of the structure. Due to the volume of fire and the need for additional resources, a second alarm was struck, bringing additional Lynnfield companies and mutual aid departments to the scene.

Firefighters mounted an aggressive interior and exterior attack, successfully bringing the fire under control at midnight. Crews remained on scene for several hours conducting overhaul, ventilation, and ensuring no further extension of the fire.

One occupant was removed from the residence by Lynnfield firefighters and was transported to a local hospital for evaluation and treatment. The extent of the injuries is unknown. No firefighters were injured during the incident.

The Lynnfield Fire Department was assisted on scene by mutual aid from Middleton, Peabody, North Reading, Reading, Wakefield, and Saugus. Stoneham and Lynn provided station coverage. Fire Chief Glenn Davis would also like to thank Cataldo Ambulance, Armstrong Ambulance, and Rehab Five for assisting at the fire scene.

The cause of the fire remains under investigation by the Lynnfield Police Department, Lynnfield Fire Department, and the State Fire Marshal’s investigative unit. Damage estimates are pending.

Davis praised the coordinated response, stating that the rapid actions of firefighters and mutual aid partners were critical to the outcome of the incident.

Residents are reminded to ensure working smoke alarms are installed on every level of their home and to practice home fire escape plans regularly.