Employees at Old Hickory Hydropower Plant take part in a simulated exercise to extract a training dummy from a confined space during a Confined Space and Confined Space Rescue Course June 14, 2018 in Hendersonville, Tenn. The U.S. Army Corps of Engineers Nashville District trained 32 employees to lead the in-house training in March 2017, which will benefit more than 200 employees across the district who require the annual training.