The U.S. Coast Guard is now saying that barges became loose in the Mississippi River after the tow vessel hit something near Cape Girardeau.

The accident happened around 10:30 a.m. Sunday. Investigators are still trying to figure out what the vessel Sheila Johnson hit near mile marker 60.

The Coast Guard says three barges carrying coal partially sank.

The tow was pushing 25 barges when 13 broke loose after impact and began driving down the river. The Bill Emerson Memorial Bridge at Cape Girardeau was closed for a little more than one hour as a precaution, but it was not struck.