CRT conducts combat training at JRTC 20-3 Published Jan. 17, 2020 By Tech. Sgt. David W. Carbajal 621st Contingency Response Wing FORT POLK, La. -- Members of the 921st Contingency Response Squadron ascended on Geronimo Landing Zone at the Joint Readiness Training Center to conduct training on combat first aid, perimeter security, and unexploded ordnance recognition and disposal.