A late afternoon fire severely damaged a three-unit apartment building on Naugatuck Avenue in Milford on Wednesday.

Fire dispatchers received multiple 911 calls at approximately 3:34 p.m. reporting a fire on the second floor of the structure located at 52 Naugatuck Ave. The first arriving units reported smoke showing from the second floor and attic windows of the 2.5 story structure. A hose line was quickly advanced into the building and extinguished the fire in six minutes, said Fire Battalion Chief Anthony Fabrizi.

The second floor unit suffered severe damage, leaving the apartment uninhabitable for the sole occupant. A first-floor tenant was home at the time of the blaze and was not injured. The three-unit structure housed a total of four occupants, Fabrizi said.

A Milford Red Cross representative arrived to provide assistance for the displaced tenant. Milford’s Fire Marshal’s division is investigating the fire. No injuries were reported.

Fabrizi said residents should remember to check their smoke and carbon monoxide detectors to make sure they are working.