Marlborough Firefighters responding to a reported structure fire at 81 Fremont Street found more than they bargained for when a large amount of chemicals were found in the basement of the home.

The call came in from a Marlborough Police motorcycle unit on routine patrol. Engines 1 and 2, Ladder 2 and Rescue 1 responded. The fire, which began in an air conditioner in a second floor bedroom area was quickly extinguished. When firefighters went into the basement to shut off the power to the affected area of the house, they found the chemicals.

The District 3 Hazmat team responded, along with the Massachusetts Department of Environmental Protection, the Hazardous Devices and Arson Investigation units from the Fire Marshal’s office, the Department of Fire Services Incident Rehab Unit as well as the City of Marlborough Police, the Office of Code Enforcement, the Board of Health and the Department of Public Works.

The hazmat teams made entry into the basement wearing Level A hazmat protection to take samples of the various products to determine what was there and how hazardous it was.

There is a fire watch and police presence at the scene to guard the property. The homeowner is cooperating with the Marlborough Fire Department and the other agencies to get the products removed in a safe manner.

While MFD units were operating with other agencies at the hazmat incident at 81 Fremont Street, Marlborough Fire Alarm received a 911 call reporting a structure fire at 184 Mechanic Street.

Engine 1, Engine 5, Ladder 2, Rescue 1 and Car 2 responded to the fire, which was in the 3rd floor stairwell. An aggressive fire attack by the crew of Engine 2 quickly knocked down the fire.

The Fire Investigation Unit, working with the State Fire Marshal determined the cause to be accidental and unintentional.

Six families were displaced by the fire; the Red Cross was called to assist them in finding temporary housing until they can return to their homes.

Damage to the structure was estimated at approximately $40,000.