The Federal Emergency Management Agency lists 56 buildings damaged or destroyed in New York City due to the September 11 attacks. Five buildings fully collapsed, three partially collapsed, 11 buildings suffered major damage, and 37 buildings sustained moderate damage. Every building of the World Trade Center either fully or partially collapsed. Beyond New York City three buildings were damaged, including the Pentagon in Arlington, Virginia, and two houses in Stonycreek Township, Somerset County, Pennsylvania.

The September 11 attacks

The September 11 attacks, also known as 9/11, were four coordinated Islamist terrorist suicide attacks by al-Qaeda against the United States in 2001. Nineteen terrorists hijacked four commercial airliners, crashing the first two into the Twin Towers of the World Trade Center in New York City and the third into the Pentagon (headquarters of the U.S. Department of Defense) in Arlington County, Virginia. The fourth plane crashed in a rural Pennsylvania field during a passenger revolt. The attacks killed 2,977 people, making it the deadliest terrorist attack in history. In response to the attacks, the United States waged the global war on terror over multiple decades to eliminate hostile groups deemed terrorist organizations, as well as the foreign governments purported to support them.The 9/11 Commission Report, pp. 1–14.

Ringleader Mohamed Atta flew American Airlines Flight 11 into the North Tower of the World Trade Center complex at 8:46 a.m. Seventeen minutes later at 9:03 a.m., United Airlines Flight 175 hit the South Tower. Both collapsed within an hour and forty-two minutes, destroying the remaining five structures in the complex. American Airlines Flight 77 crashed into the Pentagon at 9:37 a.m., causing a partial collapse. The fourth and final flight, United Airlines Flight 93, was believed by investigators to target either the United States Capitol or the White House. Alerted to the previous attacks, the passengers revolted against the hijackers who crashed the aircraft into a field near Shanksville, Pennsylvania, at 10:03 a.m. The Federal Aviation Administration ordered an indefinite ground stop for all air traffic in U.S. airspace, preventing any further aircraft departures until September 13 and requiring all airborne aircraft to return to their point of origin or divert to Canada. The actions undertaken in Canada to support incoming aircraft and their occupants were collectively titled Operation Yellow Ribbon.

The attacks killed 2,977 people, injured thousands more and gave rise to substantial long-term health consequences while also causing at least $10billion in infrastructure and property damage. It remains the deadliest terrorist attack in history as well as the deadliest incident for firefighters and law enforcement personnel in American history, killing 343 and 72 members, respectively. The loss of life stemming from the impact of Flight 11 made it the most lethal multi-plane crash in aviation history followed by the death toll incurred by Flight 175. The destruction of the World Trade Center and its environs seriously harmed the U.S. economy and induced global market shocks. Many other countries strengthened anti-terrorism legislation and expanded their powers of law enforcement and intelligence agencies. The total number of deaths caused by the attacks, combined with the death tolls from the conflicts they directly incited, has been estimated by the Costs of War Project to be over 4.5 million.

List

After the attacks, building inspections began in and around the World Trade Center site on September 12, 2001. These inspections were contracted by the New York City Department of Buildings (DoB) and the New York City Department of Design and Construction with field observations made by the Structural Engineers Association of New York (SEAoNY) as well as others. The inspections and observations were compiled by the Federal Emergency Management Agency (FEMA) and published in May, 2002. In this document FEMA categorizes buildings as "full collapse," "partial collapse," "major damage," "moderate damage," or "inspected/no damage." FEMA describes these categories in the following ways:

Full collapse"Building is not standing." Partial collapse "Building is standing but a significant portion is collapsed. All of these buildings were inspected and found to have no remaining certifiable structural capacity." Major damage "Damage to structural members requiring shoring or significant danger to occupants from glass, debris, etc."Moderate damage"Broken glass, façade damage, roof debris."Inspected"No significant damage found."

Full collapse The following five buildings are listed by FEMA in the "DoB/SEAoNY Cooperative Building Damage Assessment" from November 7, 2001, as fully collapsed. FEMA also notes that the North Bridge from Winter Garden to WTC 1 was one of the 15 buildings with the most collateral damage from the collapse of 1 and 2 World Trade center, noting that it too fully collapsed, but does not list it in this table.

+AddressCommon nameImageYear builtNotes 1 World Trade Center North Tower 1970 Collapsed approximately 1 hour and 42 minutes after being struck by American Airlines Flight 11 due to damage both from the impact and subsequent fires. 2 World Trade Center South Tower 1972 Collapsed approximately 56 minutes after being struck by United Airlines Flight 175 due to damage both from the impact and subsequent fires. 3 World Trade Center Marriott International Hotel 1981 Approximately 16 stories in the center of the building collapsed due to debris falling from the collapse of WTC 2. The rest of the building, save the lower floors at the southwest end, collapsed after being hit by debris from the collapse of WTC 1. 7 World Trade Center 7 World Trade Center1987 The collapse of WTC 1 damaged the south façade of this building, starting a series of fires across the structure. The building collapsed after these fires burned for approximately seven hours. 155 Cedar Street St. Nicholas Greek Orthodox Church 1830s Completely destroyed due to debris falling from the collapse of 1 and 2 World Trade Center

Partial collapse The following three buildings are listed by FEMA in the "DoB/SEAoNY Cooperative Building Damage Assessment" from November 7, 2001, as partially collapsed. The Winter Garden was originally listed as partially collapsed but was later revised to having "major damage."

+AddressCommon nameImageImage of damageYear builtNotes 4 World Trade Center South East Plaza Building 1975 This building largely collapsed due to impacts from falling debris from the collapse of WTC2. The remainder of the building burned from ensuing fires. 5 World Trade Center North East Plaza Building 1972 Localized collapses occurred due to debris from the collapse of WTC1. Fire then spread through much of the building. 6 World Trade Center Custom House Building 1974 Localized collapses occurred due to debris from the collapse of WTC1. Fire then spread through much of the building.

Major damage The following eleven buildings are listed by FEMA in the "DoB/SEAoNY Cooperative Building Damage Assessment" from November 7, 2001, as having sustained major damage.

+AddressCommon nameImageImage of damageYear builtNotes 125 West Street 2 World Financial Center Tower B 1987 Glazing and façade damage due to falling debris 200 Vesey Street 3 World Financial Center Tower C - Annex 1985 Column debris from WTC1 damaged the south east corner of the building. Falling debris also caused 8 of the 10 stories in the octagonal extension, or annex, of the building to collapse. 201 Vesey Street Winter Garden 1988 The east end of the building was struck by columns falling from WTC1 leading to a collapse of that section of the structure. approximately 60% of the glass panel roofing of the building collapsed and there were localized collapses throughout the roof. After shoring, the building was able to be repaired. 120 Cedar Street 120 Cedar Street - - 114 Liberty Street Engineering Building - - 130 Liberty Street Bankers Trust Building 1973 A one story section of the building was destroyed by falling debris from WTC2. One or more column sections from WTC2 impacted the south face of the building collapsing between one and three architectural bay for several floors. Virtually every window on the western side of the north face was broken by falling debris. 130 Cedar Street 130 Cedar Street - 1931 A column from WTC2 punctured the roofslab which also collapsed under the weight of debris. Fires broke out above the 9th floor. 90 West Street 90 West Street 1907 The roof and approximately half of the northern façade of the building was damaged by falling debris from WTC2. Interior floor slabs were also damaged by falling debris as well as localized fire damage. 140 West Street Verizon Building 1927 The south and east façades of the building were damaged due to falling debris from WTC1, including deformed columns and beams, and collapsed floor slabs. The east façade was further damaged on the bottom approximately 9 floors due to debris from the collapse of WTC7. 45 Park Place 45 Park Place - - Originally, this building was marked as having no damage, but upon interior inspection the landing gear from United Airlines Flight 175, which had hit 2WTC, has fallen through the roof and destroyed three floor beams in the top floor of the building. 30 West Broadway Fiterman Hall - 1959 Debris from the collapse of WTC7 caused severe structural damage to the south face of this building as well as damage to the southern half of the west façade.

Moderate damage

The following thirty-seven buildings are listed by FEMA in the "DoB/SEAoNY Cooperative Building Damage Assessment" from November 7, 2001, as having sustained moderate damage.

+AddressCommon name395 South End AvenueGateway120 West Street 1 World Financial Center Tower A120 West StreetSouth Bridge120 West Street1-2 World Financial Center Link Bridge2 Wall Street111 Broadway125 Greenwich Street90 Trinity Place110 Trinity Place120 Liberty Street124 Liberty StreetFire Station106 Liberty Street110 Liberty Street5 Carlisle1 Carlisle110 Greenwich Street1 Liberty PlazaOne Liberty Plaza10 Cortland Street22 Cortland Street27 Church StreetCentury 21189 Broadway187 Broadway9 Maiden LaneJeweler's Building174 Broadway47 Church StreetMillennium Hotel90 Church StreetPost Office12 Vesey Street26 Vesey Street28 Vesey Street14 Barclay Street100 Church Street110 Church Street120 Church Street75 Park Place224 Greenwich Street60 Warren Street128 Chambers Street

Subterranean infrastructure

Much of the World Trade Center was built over, and supported by, a six story subterranean structure. This structure contained a shopping mall, mechanical and electrical services for the center, tunnels for the NYC Subway and PATH systems, including WTC Cortlandt station and the World Trade Center PATH station, and a parking garage. This structure was covered by the 5 acre Austin J. Tobin Plaza. Due to the collapse of WTC1 and WTC2, almost 600,000 pounds of debris fell onto the plaza. This debris broke through the plaza, partially filling the 6 stories below it. At the southern side of the complex debris punched through several of the six floors, compromising the structure, but not backfilling it with debris. In October large cracks began to form on Liberty Street showing that the southern wall of the subterranean structure had begun to give way and had to be stabilized. 8 large water mains were also broken due to falling debris and collapsing structures. FEMA notes in its World Trade Center Building Performance Study, "although significant damage was sustained by the buildings, subterranean structure, and subway system, only the performances of the above grade buildings were assessed in this study." Therefore, none of the subterranean infrastructure or spaces were categorized based on amount of damage.

Beyond New York City