Firefighters responded to the scene on Thursday afternoon. About eight to 10 people were rescued.
Four people were taken to the hospital to be treated for smoke inhalation, and one also suffered an ankle injury after jumping out of the burning building.
Their injuries are not considered life-threatening. New Britain Fire Department says their names and ages are unknown at this time.
The Hartford Courant reports two firefighters were taken to the hospital for undisclosed issues. New Britain officials say the firefighters were evaluated and have been released.
Officials say the American Red Cross is assisting five families that consist of 18 adults and five children.
It’s unclear what sparked the blaze. The fire department says the house is uninhabitable, but it is not known if it will need to be demolished or not.
The cause of the fire remains under investigation.