created by varying the power to the siren. The second was the all clear - a single, continuous note. After it was confirmed the skies were clear of enemy aircraft the 'all clear' would sound.

Air-raid siren sounds the warning. Air-raid sirens first sounded the warning in London in September 1939. They became an almost daily part of life in the capital a year later during the height of ...

As German troops pushed toward Moscow, a chilling sound echoed through the frozen wastelands—the howling rockets of Stalin’s Organ. It was more than a weapon; it ...

The slots inside the stator (stay with me, this is technical) make a wooooooo sound through the honking ... and every Tuesday morning a WW2 air raid siren would go off, waking me from my slumber ...

A photo allegedly showing then-British Prime Minister Winston Churchill visiting the White House during World War II wearing a "siren-suit"— a one-piece jumper designed to "easily be slipped on ...