2nd Low Altitude Air Defense Marines demonstrate proper room clearing techniques for the Marines of Battery B, 2nd LAAD Battalion in the Military Operations on Urban Terrain town aboard Marine Corps Base Camp Lejeune, N.C., Feb. 23. - 2nd Low Altitude Air Defense Marines demonstrate proper room clearing techniques for the Marines of Battery B, 2nd LAAD Battalion in the Military Operations on Urban Terrain town aboard Marine Corps Base Camp Lejeune, N.C., Feb. 23.