GREAT LAKES, Ill. (Feb. 1, 2022) Sailors assigned to Naval Station Great Lakes participate in a simulated pat down during an active shooter drill onboard Recruit Training Command during Exercise Citadel Shield. Exercise Citadel Shield-Solid Curtain 2022 is a two-part, anti-terrorism force protection exercise that is being conducted nationwide on navy installations, Jan. 31 - Feb. 11. The annual exercise is not in response to any specific threat, but is used to evaluate the readiness of fleet and installation security programs. (U.S. Navy photo by Mass Communication Specialist 2nd Class Brigitte Johnston)