PORTSMOUTH, N.H. — Transportation crews are working to remove rust from the underside of the Memorial Bridge, which connects New Hampshire and Maine.

The work on Friday was going on about a week after a tour boat captain said he saw a piece of the bridge fall into the water.

WMUR-TV reported crews chipped at and banged on the steel beams to remove the rust on Friday. Inspectors said they would examine the underside of the bridge while crews painted areas.

New Hampshire contends the bridge and the Sarah Mildred Long Bridge, which includes a rail line serving Portsmouth Naval Shipyard, must be replaced. Maine hasn’t ruled out an option of building a single bridge to replace the two existing bridges, which are a half-mile apart.