This undated photo provided by the U.S. Air Force shows Davis-Monthan Air Force Base near Tucson, Ariz. The base was on lockdown Friday afternoon amid unconfirmed reports of gunfire. (AP Photo/U.S. ... more 
This undated photo provided by the U.S. Air Force shows Davis-Monthan Air Force Base near Tucson, Ariz. The base was on lockdown Friday afternoon amid unconfirmed reports of gunfire. (AP Photo/U.S. Air Force) less 
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Associated Press | Photo By U.S. Air Force
Fri, Sep 16, 2011 3:47 PM EDT