Ground zero

For other uses, see Ground zero (disambiguation).

In terms of nuclear explosions and other large bombs, the term ground zero (sometimes also known as surface zero as distinguished from zero point) 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 nuclear detonation and is sometimes called the hypocenter. Generally, it is also used in relation to earthquakes, epidemics, and other disasters to mark the point of the most severe damage or destruction.

Pearl Harbor

USS Arizona exploded seconds after the bomb hit Turret II of the ship towards the forward ammunition compartment.

On December 7, 1941, the Empire of Japan carried out a surprise attack on Pearl Harbor, the headquarters of the United States Pacific Fleet in Honolulu, Hawaii. At the time of the attack, the U.S. and Japan were not officially at war and were still negotiating for a possible peace treaty. The event was described as ground zero due to the catastrophic damage inflicted upon the fleet and facilities within the naval base and other areas, as well as the nature surrounding the attack. The attack started at 7:55 am with 353 Japanese planes and lasted for 110 minutes. The most famous example of ground zero was Turret II of the USS Arizona, when an armor-piercing bomb penetrated through that turret towards the forward ammunition compartment which blew the ship apart and sunk it within seconds, killing 1,177 out of the 1,512 people on board. Hickam Field was also described as ground zero due to the devastation the Japanese caused to the airfield, killing 189 people and destroying many aircraft on the ground. In total, 2,467 people were killed in the attack, including 2,403 victims and 64 attackers, and eight battleships and 217 aircraft (including 19 from the attackers) were destroyed, making it the largest peacetime loss of life and property on American soil.

On December 8, the day after the attack, Japan declared war on the United States and the United States declared war on Japan in return the same day, thus drawing the United States into World War II and turning the Allied tide against the Axis powers in the war.

Trinity, Hiroshima, and Nagasaki

In mapping the effects of an atomic bomb, such as on the city of Hiroshima here, concentric circles are drawn centered on the point below the detonation and numbered at consecutive distances. This point below the detonation is called "Ground Zero".

The origins of the term "ground zero" began with the Trinity test in Jornada del Muerto desert near Socorro, New Mexico, and the atomic bombings of Hiroshima and Nagasaki in Japan. The Strategic Bombing Survey of the atomic attacks, released in June 1946, used the term liberally, defining it as: "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, an embedded reporter with the Manhattan Project, reported that "Zero" was "the code name given to the spot chosen for the [Trinity] test" in 1945.

The Oxford English Dictionary, citing the use of the term in a 1946 New York Times report on the destroyed city of Hiroshima, defines ground zero as "that part of the ground situated immediately under an exploding bomb, especially an atomic one." The term was military slang, used at the Trinity site where the weapon tower for the first nuclear weapon was at "point zero", and moved into general use very shortly after the end of World War II. At Hiroshima, the hypocenter of the attack was Shima Hospital.

Panoramic view of the monument marking the hypocenter, or ground zero, of the atomic bomb explosion over Nagasaki.

The Pentagon

Cafe Ground Zero in the Pentagon's center courtyard.

The Pentagon, the headquarters of the United States Department of Defense in Arlington County, Virginia, was thought of as the most likely target of a nuclear strike during the Cold War.

During the September 11 attacks, when the Pentagon was hit by American Airlines Flight 77 commandeered by five Al-Qaeda hijackers, the east-side of the building was under renovations, so that part of the building was empty during the attack. The strike on the Pentagon killed 70 civilians and 55 military personnel in the building, as well as the 59 civilians and the five hijackers on board the aircraft. Part of the renovations was to add reinforcers to the concrete walls and to add blast proof windows and walls. Because some of this renovation work was already completed, it saved the hundreds of lives.

The open space in the center of the Pentagon is informally known as ground zero, and a snack bar located at the center of this plaza was nicknamed "Cafe Ground Zero".

World Trade Center

Underground damage days after the 1993 bombing of the garage underneath the North Tower of the World Trade Center.

The World Trade Center site, as it appeared in October 2004.

Aerial view of the World Trade Center site, as it appeared in September 2001.

On February 26, 1993, Islamic terrorists attacked the World Trade Center in New York City by detonating a car bomb underneath the garage of the North Tower, hoping to topple the North Tower over to the South Tower, and thus killing thousands of people. However, the tower complex withstood but the bombing killed six civilians and injured 919 others, 88 firefighters, and 35 law enforcement officers. The damage to the garage of the World Trade Center's North Tower was so extensive that the U.S. television docudrama The FBI Files' Season I of Episode 11 (which aired on February 9, 1999, about the 1993 World Trade Center bombing) used the term ground zero.

On September 11, 2001, the World Trade Center was struck again as part of the September 11 attacks when American Airlines Flight 11 and United Airlines Flight 175 hijacked by 10 Al-Qaeda terrorists flew into the North and South towers, respectively, causing massive damage to both towers during impact, and starting fires that caused the weakened 110-story skyscrapers to collapse, killing all 147 civilians and 10 hijackers on board the two aircraft, as well as 2,192 civilians, 71 law enforcement officers, and 343 firefighters in and within the vicinity of the towers. Since the attacks, especially in the United States and the media, "Ground Zero" is generally understood to mean the World Trade Center site. The phrase was being applied to the site within hours after the towers collapsed. It appears that the first use of the term on a mainstream North American media outlet in reference to the September 11 attacks was at approximately 11:55 am when an eye witness who claimed to be a Fox News freelancer referred twice to ground zero. He may also have been the first person to suggest the cause of the collapse of the towers was due to "structural failure due to fires". At 4:41 p.m., in an interview with Peter Jennings on ABC News, attorney and survivor of

the attacks Tom Humphreys (spelled "Humphries" on air) said, in reference to the collapse of the South Tower, that

The tragedy is that the police and fire personnel that tried to help people out of that building were right at Ground Zero when that happened...

The next known reference occurred at 7:47 p.m. (EDT) on that day, when CBS News reporter Jim Axelrod said:

Less than four miles behind me is where the Twin Towers stood this morning. But not tonight. Ground Zero, as it's being described, in today's terrorist attacks that have sent aftershocks rippling across the country.

The term "Ground Zero" was simultaneously used by NBC News reporter Rehema Ellis when her own report was aired on NBC at around the same time as Jim Axelrod's report on CBS News. She said:

We're now just a block away from the World Trade Center and the closer we get to "ground zero" the harder it is to breathe and to see.

Rescue workers also used the phrase "The Pile", referring to the pile of rubble that was left after the buildings collapsed. Even years later, the term "Ground zero" has become a shorthand for the site, even after construction on the new One World Trade Center and the National September 11 Memorial & Museum were well under way. A controversial planned Islamic cultural center that was to have been built several blocks from the former World Trade Center site was criticized by opponents seeing to stop the project as the "Ground Zero mosque." In advance of the 10th anniversary of the attacks, New York City mayor Michael Bloomberg urged that the "Ground zero" moniker be retired, saying, "... the time has come to call those 16 acres what they are: The World Trade Center and the National September 11th Memorial and Museum." Ground Zero, in New York City, now has a memorial and underground museum to remember this day in history and the people that lost their lives. There are two reflecting pools located where the Twin Towers once stood. Engraved around the edges of these pools are the names of the 2,983 victims who were killed in the September 11 attacks and the 1993 World Trade Center bombing. The underground museum will display exhibits of the stories from victims, witnesses, and responders on this day.