Old Lyme — A fire that severely damaged the kitchen of The Grille on Shore Road has been ruled accidental, a fire official said Monday.

Fire Marshal David Roberge said that a properly installed and insulated stove was in the vicinity of an empty junction box. He said through time heat from the stove would enter the junction box and eventually weakened the ignition point of the wood in the wall, causing the fire.

Roberge said the property owner is working on isolating the damage in the kitchen and a cleaning crew is working on cleaning the rest of the restaurant.

He said the owner is hoping to reopen by the end of the week.

The Old Lyme Fire Department was called out shortly before 2 p.m. Friday. Firefighters at the scene pulled apart a portion of the kitchen wall to find fire inside, and prevented it from spreading into the ceiling void and an apartment above the restaurant.