Army Reserve Sgt. Aaron Contreras demonstrates how C4 explosives cut a rail in a controlled detonation during explosives training at Fort Hunter Liggett, Calif., July 26, 2015. Army Reserve Sgt. Aaron Contreras demonstrates how C4 explosives cut a rail in a controlled detonation during explosives training at Fort Hunter Liggett, Calif., July 26, 2015. SHARE: Download: Full Size (1.669355 MB) Tags: Photo Essays Credit: VIRIN: 458022-G-TZI58-002.jpg Photo Gallery