Six people were killed and at least nine others were injured in a fiery nine-vehicle pileup Thursday night on Interstate 75 in Tennessee, Chattanooga police said. Few details were immediately available because emergency crews were still at work, Chattanooga police said. At 11 p.m., four hours after the wreck, state traffic cameras showed the scene still littered with vehicles as police and state troopers worked to remove victims from the scene.The state Department of Transportation said the crash involved at least one cargo-carrying semi-trailer.