A U.S. U-2 spy plane has crashed in southwest Asia, but the military has not disclosed the location of the crash or any of the circumstances. The U.S. Air Force, in a short written statement, said the cause of the crash and the fate of the U-2 pilot was not known. The U-2, a single-seat jet able to fly at high altitudes on surveillance missions, has been flown by the U.S. Air Force for over 50 years. CNN quoted Officials as saying that the plane went down Tuesday evening.