Mr. Luis A. Diaz, US Department of Transportation, Federal Aviation Administration, instructs US Army (USA) Reserve personnel assigned to the 125th Military Police Battalion, Puerto Rico National on metal detectors at the Luis Munoz Marin International Airport at San Juan, Puerto Rico. Members of the National Guard were mobilized in response to request for higher security at airports across the nation in the aftermath of the September 11th terrorist attack on the World Trade Center and the Pentagon