U.S. Air Force Master Sgt. Daniel Martin inspects the pop-up security barrier at the inbound Rivers Avenue gate entrance at Joint Base Charleston, S.C., March 23, 2010. Sergeant Martin was at the gate to weld more steel to the barrier for reinforcement. Sergeant Martin is the NCO in charge of the structure shop with 628th Civil Engineer Squadron. (U.S. Air Force photo/James Bowman/released)

U.S. Air Force Master Sgt. Daniel Martin welds steel onto the pop-up security barrier at the inbound Rivers Avenue gate entrance at Joint Base Charleston, S.C., March 23, 2010. Sergeant Martin was at the gate to weld more steel to the barrier for reinforcement. Sergeant Martin is the NCO in charge of the structure shop with 628th Civil Engineer Squadron. (U.S. Air Force photo/James Bowman/released)

U.S. Air Force Master Sgt. Daniel Martin removes a slag, which is the residue leftover after welding, from the pop-up security barrier at the inbound Rivers Avenue gate entrance using a chipping hammer on Joint Base Charleston, S.C., March 23, 2010. Sergeant Martin was at the gate to weld more steel to the barrier for reinforcement. Sergeant Martin is the NCO in charge of the structure shop with 628th Civil Engineer Squadron. (U.S. Air Force photo/James Bowman/released)

U.S. Air Force Master Sgt. Daniel Martin welds steel onto a pop-up security barrier at the inbound Rivers Avenue gate entrance on Joint Base Charleston, S.C., March 23, 2010. Sergeant Martin was the gate to weld more steel to the barrier for reinforcement. Sergeant Martin is the NCO in charge of the structure shop with 628th Civil Engineer Squadron. (U.S. Air Force photo/James Bowman/released)

U.S. Air Force Master Sgt. Daniel Martin uses a wire brush to remove slag, which is the residue leftover after welding, from the pop-up security barrier at the inbound Rivers Avenue gate entrance on Joint Base Charleston, S.C., March 23, 2010. Sergeant Martin was at the gate to weld more steel to the barrier for reinforcement. Sergeant Martin is the NCO in charge of the structure shop with 628th Civil Engineer Squadron. (U.S. Air Force photo/James Bowman/released)