SNOW SCENARIO U.S. Air Force Senior Airman Kristi Terwilliger, back, and Staff Sgt. Benjamin Pieta take aim in the prone position during an operational readiness exercise on Ellsworth Air Force Base, S.D., May 12, 2010. Pieta and Terwilliger are patrolmen assigned to the 28th Security Forces Squadron. SHARE IMAGE: Download Image: Full Size (0.06 MB) Photo By: VIRIN: 081949-V-ROA94-339.jpg Photo Gallery