At approximately 0820, an eastbound Norfolk Southern train traveling from Birmingham, AL to Chattanooga, TN collided with a Clean Harbor tractor trailer rig at a crossroads near mile post 5.85 in Hamilton County, TN. As a result of this collision, three locomotives and 10 of the 100 rail cars overturned and released approximately 5000 gallons of diesel fuel from one locomotive onto the ballast and surrounding area. Two other diesel-laden rail cars with 10000 gallons of diesel fuel threaten to discharge their contents during the righting process. EPA has coordinated with responding local and state environmental programs to investigate the site and potential impacts to environmentally sensitive areas and to determine the potential for off-site migration via streams and tributaries to the Tennessee River. Downstream notifications were made collaterally between EPA, TDEC. OSC Englert was mobilized to assist local and state authorities with overseeing the clean-up operations and to insure that the diesel fuel does not migrate off-site and into waterways due to adverse weather conditions presently impacting the Chattanooga area.