LOUISVILLE, Ky. (WDRB) -- An oil spill has closed part of the Mississippi River along the Kentucky border. 

Two tow boats collided Wednesday night near Paducah. A cargo tank carrying oil ruptured, sending the oil into the river. 

It's not known how much of the oil spilled. A 16-mile span of the river is closed.

The U.S. Coast Guard is working to clean up the spill. 

The cause of the collision is still under investigation.

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