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Attack Warning System : Portland Map showing location of sirens |
12/31/1952 at 9:14:02 AM |
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Attack Warning System : Portland Map showing location of the sirens and there previously planned location |
12/31/1952 |
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Attack Warning System : Portland Map tentative location for sirens |
12/31/1952 |
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Blueprint Plan : Air raid siren platform, American Bank Building |
07/10/1953 |
