Firefighters responded to a house fire at 19 Diamond Street in Naugatuck at 11 a.m. on Tuesday and closed several streets as they battled the fire.
No injuries are reported and everyone was out of the house, officials said.
Firefighters closed Spring Street, between Bridge, Anderson and Diamond streets.
Spring Street has reopened, but Diamond Street remains closed.
Residents are encouraged to use alternate routes to avoid being delayed.
Officials have not said anything about pets in the building, but residents said they saved only one of 12 cats in unit.
