One of the numerous training blocks that these Air Force security forces will go through during their 4-6 week stay prior to departing for Southwest Asia is being gassed. The first Grenade or two thrown by the Silver Flag Alpha instructors/cadre is a regular smoke grenade to determine wind direction. The following four to six grenades are CS or Riot control. In this photo the majority of students have don their gas masks and are slowly walking out of the cloud of CS gas or an advanced version of tear gas. While another member helps a fellow student who did not don his mask and is suffering from the gas.