A section of Interstate 75 through central Kentucky has been shut down because of a chemical spill, prompting both the north and southbound lanes to be closed. KSP says more than 3,000 gallons of ferric chlorids was spilled and one officer was taken to a hospital; no word on that person's condition.  Troopers have shut down all lanes of the interstate from northbound exit 90 to southbound exit 97.  There's no word on how long the cleanup will take.  Traffic is being rerouted onto U.S.  25.