Freighter carrying salt runs aground near Detroit's Belle Isle.

A freighter carrying 20,000 metric tons of rock salt ran aground in the Detroit River near Belle Isle, but was freed several hours later with the help of a tugboat. The cause of the incident is still unknown, but the ship's owner is investigating. No injuries or pollution were reported. The Mark W. Barker is a relatively new and large vessel, christened last year, and is the first large bulk carrier built on the Great Lakes since 1981.