U.S. Marines with 3rd Battalion, 11th #Marines, 1st Marine Division, participate in a #livefire exercise during Steel KnightSawn Blitz (SKDB) 21 on Marine Corps Air Ground Combat Center Twentynine Palms, California, Dec. 8, 2020. Exercise SKDB 21 is a unique opportunity for 1st #Marine Division to achieve its training objectives while also supporting naval maneuver and fleet-level objectives. (U.S. Marine Corps video by Lance Cpl.