Twenty people were rescued Sunday afternoon when they became trapped in the gorge below Great Falls Dam as water flooded the area and forced them to take refuge on higher ground.The call for help sent rescue workers scrambling because there have already been three people to drown at the state park this summer.While TVA is investigating the incident, normal procedure is for sirens to sound and lights to flash within the gorge several minutes prior to the release of water in order to give those in the gorge time to get out. Graham believes those who were in the gorge were not from Warren County and were not familiar with the gorge and its rapidly rising water.The release of water sent those in the gorge scrambling, heading for higher sections to escape the current.“That’s basically the only thing you can do, head for higher ground if you’re caught down there during a release,” said Sheriff Jackie Matheny, whose office has worked several swift-water rescues in the gorge over the years.Those caught in the gorge Sunday were all able to get to safety, although rescue workers from the park along with White and Warren County rescue squads had to pull a few from the area using ropes so they could safely navigate the swift waters below the dam. The water release was eventually stopped by TVA to allow completion of the rescue.In the end, one tourist complained of a noncritical knee injury as a result of scrambling to safety.