AUGUSTA — No one was injured in an early-morning fire at the Senator Inn & Spa that destroyed 15 back units of the landmark hotel off Western Avenue, officials said.

The Office of State Fire Marshal investigated the scene on Friday and determined the fire started accidentally in an attic over one of the units of the “Governor’s Wing,” which is a detached unit behind the main hotel.

Augusta Fire Department Chief Scott Dunbar said a person walking by the hotel, located at 284 Western Ave., reported the blaze at 12:29 a.m. after seeing flames going through the roof of a building.

The fire engulfed the back units of the Senator Inn and destroyed them all. The back units, used only during the summer season, are individual motel-style rooms with doors facing the parking lot and were unoccupied at the time of the fire, but were being renovated. They are detached from the main hotel building, which was not damaged, Dunbar said.

“We came as the fire was reportedly going through the roof and when we got there, it surely was going through the roof and we called mutual aid,” Dunbar said early Friday morning.

Fire marshal investigators were responding to the scene Friday morning, when the city fire crews started to clear out around 6 a.m., Dunbar said.

Central Maine Power cut the power to the hotel to minimize any potential damage from the fire, which Dunbar said is standard practice. The power was restored to the commercial area by Friday morning.

The Augusta Fire Department called mutual aid from Togus, Gardiner , Sidney, Vassalboro, Manchester, Chelsea and Hallowell fire departments.

Kaitlyn Martin, general manager of the Senator Inn & Spa, said Friday morning that she didn’t yet have the estimated cost of the damage caused by the fire, but said hotel officials intend to rebuild the back units.

Martin said the destroyed units were used to house seasonal workers from June to September.

“Our hope is that we can of course rebuild — rebuilding the building would be the best case scenario,” Martin said. “It’s going to take some time to understand the severity of the damage … We have been a staple to the community for a long time.”

The hotel was built in 1955 on Senator Way as the Senator Motel with a single wing of hotel rooms, a restaurant and cocktail bar, Marin said. Over the years, the building received renovations and became the hotel it is today with 108 rooms, at a key location near the Interstate 95 on-ramps that is at the gateway to the heart of Maine’s capital city.

“It’s really a place where we can offer a unique experience for people — we are not your standard corporate hotel where you can go anywhere in the country, or state where it’s the same everywhere,” Martin said. “It’s very unique.”

Editor’s note: An earlier online version of this story incorrectly listed the number of units in the affected wing as 12. It was a source error.