ground zero

Meanings

1. Originally, the point on the land or water surface below which a nuclear bomb detonates in the air; now also the point on such a surface at or above the detonation.
2. The location of any disaster or violent assault.
3. The point at which something begins.

1. The site of the former World Trade Center towers in New York City destroyed on 11 September 2001.

Etymology

From ground + zero, first attested in a June 1946 a report by the United States Strategic Bombing Survey on the atomic bombing of Hiroshima and Nagasaki, Japan, on August 6 and 9, 1945, during World War II. “Zero” was used as the code name for the location of the Trinity atomic bomb test – the first detonation of a nuclear weapon – in New Mexico, USA, on July 16, 1945.