New London ― Firefighters on Friday night battled a house fire on Connecticut Avenue that heavily damaged the 100-year-old structure and left the owner displaced.

Flames could be seen coming from the second floor of the colonial-style home at 154 Connecticut Ave. at 7:45 p.m. as firefighters used chainsaws to cut through the roof and smashed out windows to vent plumes of smoke.

Fire Chief Thomas Curcio said there were no injuries but four people were displaced by the fire and are being assisted by the Red Cross. He said arriving crews heard one or two “pops” that may have been suspected ammunition cooking off because of the heat.

Michele Kilpatrick, co-owner of the home she’s lived in 22 years, said she was the residence’s only occupant when the fire broke out at approximately 7:30 p.m. She said her cat was still missing.

“(The fire) probably started with the electrical, either the air conditioning or a fan,” she said.

A large crowd gathered within a few feet of the burning home as firefighter hose crews poured water into the flames, which were extinguished within seconds.

In addition to the New London department, firefighters from Waterford along with the Naval Submarine Base, Norwich and Electric Boat departments responded to the fire along with emergency medical personnel from Groton Ambulance.

The fire marshal is investigating the cause of the fire.

j.penney@theday.com