Officials put out a fire at an apartment building in Brookline.
Brookline Police and Fire crews responded to the fire on Aspinwall Avenue.
Officials believe the fire started in the first floor bedroom.
Crews initially though the fire may have been related to a drug lab, but confirmed that was untrue once they arrived on scene.
Police said four people were taken to the hospital, including one elderly resident. Crews also rescued two cats and took them to an animal hospital.
There is no information on the cause of the fire.