It happened in Windham County at the Midway Restaurant in Ashford around 11:45 p.m., Saturday, Aug. 20.
First-arriving firefighters found flames at the back of the building and through the roof of the lounge area, said Ashford Fire Chief Paul Varga.
Firefighters worked for several hours to bring the blaze under control at 1:45 a.m., Sunday, Aug. 21, Varga said.
Crews remained on the scene for several hours for overhaul and to check for flare-ups, officials said.
The cause of the fire is under investigation by the Ashford Fire Marshal, with assistance from the state fire marshal's office.
There were no civilian or firefighter injuries
The fire was contained to the lounge area, however, much of the building sustained smoke and water damage, Varga said.
The restaurant will remain closed for an undetermined amount of time, he added.
Click here to follow Daily Voice Fairfield and receive free news updates.