A fire has damaged an outbuilding at the historic Dunleith Plantation in Natchez.

The building, part of the plantation dating back to the 1850s, was being used for offices and a gift shop. Firefighters said Thursday’s fire is under investigation.

The fire left bricks scorched and portions of the roof caved in.

The upstairs was a complete loss, but the downstairs will be somewhat salvageable despite fire and water damage, said General Manager John Holyoak said.

Historically, the building was used to house poultry, he said.

Ron Miller, executive director of the Historic Natchez Foundation, said the key to saving a historic building once it has been damaged is to repair the roof as quickly as possible.

“Once it loses its roof, it can fall apart pretty quickly,” he said.

Dunleith has no plans to allow the building to suffer any more damage, Holyoak said.

“We’re getting back to business and will start rebuilding immediately,” he said. “We won’t miss a beat.”