National September 11 Memorial & Museum

The National September 11 Memorial & Museum (known separately as the 9/11 Memorial and 9/11 Memorial Museum) are the principal memorial and museum, respectively. They commemorate the September 11, 2001, attacks, which killed 2,977 victims, and the World Trade Center bombing of 1993, which killed six. The memorial is located at the World Trade Center site, the former location of the Twin Towers, which were destroyed during the September 11 attacks. It is operated by a non-profit corporation whose mission is to raise funds for, program, own, and operate the memorial and museum at the World Trade Center site.

A memorial was planned in the immediate aftermath of the attacks and destruction of the World Trade Center for the victims including those involved in rescue operations. The winner of the World Trade Center Site Memorial Competition was Israeli architect Michael Arad of Handel Architects, a New York- and San Francisco-based firm. Arad worked with landscape-architecture firm Peter Walker and Partners on the design, a forest of trees with two square pools in the center where the Twin Towers stood. In August 2006, the World Trade Center Memorial Foundation and the Port Authority of New York and New Jersey began heavy construction on the memorial and museum. The design is consistent with the original Daniel Libeskind master plan, which called for the memorial to be 30 feet (9.1 m) below street level—originally 70 feet (21 m)—in a plaza, and was the only finalist to disregard Libeskind's requirement that the buildings overhang the footprints of the Twin Towers. The World Trade Center Memorial Foundation was renamed the National September 11 Memorial & Museum in 2007.

Ground zero

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

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.