Boston firefighters responded to 110 Livermore St., an apartment building off Cummins Highway in Mattapan, for a basement laundry-room fire that was being fed by an incoming gas main, around 12:30 p.m. on Saturday.

The fire started with an explosion, the Boston Fire Department reports. Shortly after 12:50 p.m., firefighters were able to shut off the flow of gas to the building and knocked down the fire.

The department says nobody was injured, but that all of the residents of the building's 40 apartments were displaced.

Damage was estimated at $200,000.