Fire investigators were probing the roof of Boogies Diner on Main Street near Redwood Avenue after an early morning fire at the restaurant and lounge.
The call came in about 4:12 a.m., and, with emergency vehicles at the scene, police closed down a stretch of Main between Mountain and Burrows avenues.
The rooftop fire was extinguished quickly, and Main was reopened about 6 a.m.
It's believed no one was inside at the time of the blaze.
Damage to the building is estimated at $100,000. A cause of the fire has not been determined, and it remains under investigation.