PADUCAH, Ky. - On-scene assessment teams have reported the maximum estimated potential clarified slurry oil released from the tug collision is now 250,000 gallons, Thursday.The maximum potential spill has been reduced because the two remaining partitions aboard the affected barge were reportedly secured.A Coast Guard HC-144 Ocean Sentry fixed wing aircraft conducted an over flight earlier today, which revealed a five-mile discoloration beginning at the impact site.A safety zone is in place on the Mississippi River, and currently closed to all traffic except response vessels between mile markers 939-922. A queue is in place, six up bound and nine down bound.Coast Guard Sector Ohio Valley watchstanders received a call about a collision between two towboats at mile marker 937 at 8:22 p.m. Wednesday.The Coast Guard is working with the barge owner and SWS, an oil spill response organization, to determine the amount of slurry oil that has been discharged.The cause of the collision is currently under investigation.