150203-N-IS680-259 VIRGINIA BEACH, Va. (Feb. 3, 2015) Officers from the Virginia Beach Police Department arrive to assist Naval Air Station (NAS) Oceana security forces during an active shooter drill at NAS Oceana as part of Exercise Solid Curtain-Citadel Shield 2015. Solid Curtain-Citadel Shield is the Navy�s largest annual force protection exercise designed to test the service�s security forces to respond to threats to installations and units. (U.S. Navy photo by Mass Communication Specialist 2nd Class Alysia R. Hernandez/Released)