Commercial vessel traffic in the St. Marys River was shut down after the 629-foot US bulk carrier Calumet ran aground on the north side of Sugar Island, the United States Coast Guard said.

The bulk carrier departed Essar Steel in Sault Ste. Marie, Ontario and was transiting downbound on the St. Marys River to its next port of call in Brevort, Michigan, when it ran into trouble in the evening hours on August 9. The vessel was not carrying any cargo.

The Army Corp of Engineers conducted an assessment of the river bottom around the vessel, while the divers’ initial assessment determined that the vessel’s stern is structurally sound.

Grand River Navigation, the owner of the ship, has hired an Oil Spill Removal Organization to place boom on the surface of the water near the front of the vessel to protect the environment as a precaution.

The St. Marys River will remain closed to commercial vessels from the Soo Locks to 6 Mile Point.

Grand River Navigation developed a salvage plan which would be presented to the US Coast Guard for review and approval.

The cause of the grounding is under investigation, the USCG added.