The site of the former Twin Towers has, since 9/11, been known as Ground Zero, in an almost sacred way.
The term predates 9/11 and has been used for the location of any major damaging or disastrous event, including earthquakes, tsunami and tornado touch downs.
The term ground zero describes the point on the Earth's surface closest to a detonation. In the case of an explosion above the ground, ground zero refers to the point on the ground directly below the detonation
In military use it is therefore sometimes also referred to as surface zero.
It is not to be confused with the military term zero point, which is the centre of a burst of a nuclear weapon at the instant of detonation. The zero point may be in the air, or on or beneath the surface of land or water, depending upon the type of burst.
Although the term has often been associated with nuclear explosions and other large bombs, it is also used in relation to earthquakes, epidemics and other disasters to mark the point of the most severe damage or destruction. The term is also often used for disasters that have a geographic or conceptual epicentre.
The term originated with the Manhattan Project, the research and development program that developed the Atomic Bomb during WW2 and was responsible for the bombing of Japan. After Hiroshima and Nagasaki were levelled by atomic bombs in 1945, the United States Army Air Forces (a component of the US Army and the WW2 predecessor of the US Air Force) carried out a survey of the impact of the atomic attacks. Known as The Strategic Bombing Survey, it was released in 1946. It included the following:
"For convenience, the term 'ground zero' will be used to designate the point on the ground directly beneath the point of detonation, or 'air zero'. "
William Laurence, a reporter attached to the Manhattan Project, reported that "Zero" was "the code name given to the spot chosen for the atomic bomb test in 1945.
In 1946 the Syracuse Herald Journal quoted from the Strategic Bombing Survey, the first use of the term in public print:
“There is reason to believe that, if the effects of blast and fire had been entirely absent from the bombing, the number of deaths among people within a radius of one-half mile from ground zero (the point on the ground directly under the bomb’s explosion in the air) would have been almost as great as the actual figures.”
Syracuse Herald Journal, 1 July 1946.
The monument marking the hypocenter, or ground zero, of the atomic bomb explosion over Nagasaki.
The term may have had its origins in military slang in use earlier. When the US detonated its first atomic device in a test on 16 July, 1945 at the Trinity site in New Mexico, the site of the tower supporting the device was referred to as “Point Zero:”
Especially in the past decade, it has frequently been confused or merged with back to square one:
“It just so happened we raised the exact amount of money to meet the purchase price,” O’Toole says. “Now we’re back to ground zero, and we have to start over again.”
Pittsburgh Tribune-Review, 14 Dec. 2008.
It has also been used in a figurative sense for the focal point of some event or situation, the starting point of some endeavour or the kernel of a developing situation:
“Darting through six decades, capturing his passions on film, Avedon has had a knack for locating himself at ground zero of American culture.”
Newsweek, Sep. 1993.
“Instead of making cuts based on the current school year’s budget, Sina said, the system will start from ‘ground zero’ and build based on what each school needs.”
Washington Post, 21 Jan. 2010.
During the Cold War the Pentagon, the headquarters of the US Department of Defence in Arlington, Virginia was thought of as the most likely target of a nuclear missile strike. The open space in the centre is informally known as ground zero. A snack bar located at the centre of this plaza was nicknamed "Cafe Ground Zero".
In September 2011, in advance of the 10th anniversary of 9/11, NY Mayor Michael Bloomberg made a speech in which he stated:
“We will never forget the devastation of the area that came to be known as ‘Ground Zero.’ Never. But the time has come to call those 16 acres what they are: The World Trade Center and the National September 11th Memorial and Museum.
Negative criticism resulted in a later clarification. According to the Mayor’s spokesperson:
"The speech was about the future, about moving on and rebuilding Lower Manhattan. The name 'Ground Zero' is associated with the events of 11 September 2001 and the World Trade Center is part of the future."
"Ground Zero means there's nothing there but now they're rebuilding and they've done a beautiful job, we need to forget it. I like 'The World Trade Center and September 11 Memorial'. It's more appropriate."
- Ester Di Nardo, who lost her daughter Marisa in the attacks.
"It has a strong national resonance but there's a strong case to be made for moving away from it. It's now a bustling site with buildings going up, but Ground Zero keeps it fixed to that moment when the towers fell. But you can't change language by edict. [The Mayor’s preferred term is] more symbolic, reflecting a particular perspective because he wants New York to be forward-looking."
Lexicographer Ben Zimmer