Firefighters responded in Chelsea Monday after a fire broke out on a porch, officials said.
The incident happened in a building off Garfield Avenue.
Video later showed smoke and flames visible as fire spread along the porch.
Officials said fire investigators were looking into fireworks as a possible cause after neighbors told firefighters there had been people setting off fireworks across the street.
The fire did not spread to an adjoining apartment and no one was hurt, officials said.
An investigation by the Massachusetts State Police was ongoing as of Monday night.
