Following two security breaches earlier this summer, Hartsfield-Jackson International Airport in Atlanta, Georgia, has begun installing concertina wire on fencing around the airport perimeter.

The Atlanta Journal-Constitution reports that the coiled razor wire is being added on top of the existing three rows of barbed wire on around 20 miles of perimeter security fencing that surrounds the airport.

The wire is being installed at a rate of around 450 feet per day, costing approximately $5 million in total, to be paid for with airport funds.

Additional measures are still being considered, such as covering the chain link fence with fabric to make it more difficult to climb, or including a v-shaped structure on the concertina wire.

The move is in response to several security breaches over the summer, including a man who scaled a fence and ran onto an active taxiway and a trespasser walking on an access road insider the perimeter fence in the early morning.