Airmen check their equipment before driving to a hazardous chemical scenario site at the Center for National Response in W.Va., March 27, 2014. The approximately half-mile long Memorial Tunnel is one of many venues the CNR offers for consequence and crisis management emergency response exercises. The tunnel itself also offers replicas of a post office, rail station, chemical labs, an Afghanistan tunnel, rubble room and a metro rail car. (U.S. Air Force Photo/ Airman 1st Class Nesha Humes)