Boston firefighters responded around 8 p.m. to 31 Mercer St., for a two-alarm fire that started on the third floor and spread to the roof.
The Boston Fire Department reports one person on the third flood was rescued from the flames and taken to a local hospital. Another resident and three firefighters also required medical attention, but none of the injuries are considered life threatening, the department reports.
The fire was reported knocked down around 8:25 p.m.
The cause of the fire, which did an estimated $800,000 in damage and displaced five people, is under investigation, the department says.