A fire that damaged a storage shed at Bath Iron Works on Saturday will be investigated by federal agencies, according to the Bath Fire Department.

The fire started about 4 p.m. outside a ship that is under construction on land in the shipyard at 700 Washington St., fire Capt. Marc Wood said.

The fire was largely contained to a structure below the ship that was used to store equipment and supplies, Wood said. The BIW fire department quickly got the blaze under control, and Bath firefighters finished the job, he said, with crews returning to the fire station about 6:15 p.m.

“No one was working on the ship at the time, but people were in the area,” Wood said. “One employee was taken to a hospital for treatment of non-life-threatening injuries.”

The ship sustained no obvious damage, Wood said. However, because BIW is a military contractor, the Navy and other federal agencies will join local and state fire officials in what could be a lengthy investigation, he said.

The cause probably was electrical, Wood said, but there are many flammable materials at the industrial site, so the fire warrants a thorough investigation.