Philippines. (United States). 1941. Air Mail envelope addressed to Clark Field, Philippines bearing United States SG 811, 10c brown-red (pair) and Air Mail SG A852, 30c blue (2) tied by Leechburg PA. duplex 'Dec 6 1941' with instructional 'Returned To Sender/ Service Suspended' in violet on face. Attractive item mailed one day before the attack on Pearl Harbour.