Workers begin the process of removing the pop-up barriers located near the main gate at Niagara Falls Air Reserve Station, N.Y. on March 7, 2012. Several issues including possible environmental impact is the reason a decision was made to replace them. Pop-up barriers are one of many standard measures used to help protect people who work and visit federal facilities. An integral part of the new system is manufactured locally by a western New York company. The main gate is scheduled to be closed until the end of March when work is completed on the barrier. (US Air Force photo by Peter Borys)