Freighter that ran aground in St. Clair River freed Tuesday night

Coast Guard officials are investigating what caused a ship to run aground until it was freed almost 12 hours later Tuesday in the St. Clair River near Marine City.

The Coast Guard first learned of the incident at 7:21 a.m., according to a statement from its Ninth District. A tug crew refloated the freighter at about 7 p.m. , said the Ninth Coast Guard District Great Lakes.

The ship, known as the American Courage, is a 617-foot lake freighter carrying 20,000 tons of stone.

“With no injuries or pollution reported, our plan is to refloat the American Courage and coordinate with partner services for assistance and safe navigation," said Lt. j.g. Adeeb Ahmad, USCG Sector Detroit's public affairs officer.

A helicopter from a Detroit air station was sent to the scene alongside a small boat from a station in Port Huron.

The Coast Guard had said it was coordinating with freighter owner Grand River Navigation to refloat the freighter.

USCG has also launched a full investigation to evaluate the effect on vessel safety.