1 World Trade Center (1970–2001)
| Company type | Office skyscraper |
|---|---|
| Industry | Commercial real estate |
| Founded | 1972 |
| Defunct | 2001-09-11 |
| Fate | Destroyed in the September 11 attacks |
| Successor | One World Trade Center (new) |
| Headquarters | New York City , United States |
| Products | Office space |
The original One World Trade Center—also referred to as the North Tower, Tower 1, or simply 1 WTC—was part of the Twin Towers within the initial World Trade Center complex located in New York City. Completed in 1972, it soared to a height of , making it the tallest building worldwide until 1973, when Chicago's Sears Tower overtook it.
Identifiable from its counterpart, the original South Tower, by a rooftop telecommunications antenna, the North Tower reached an overall height of , including this antenna. Notable architectural elements included a canopy on the western facade and pedestrian bridges linking it to Three and Six World Trade Center at plaza level—features not present on the South Tower. The building's official address was 1 World Trade Center, and due to the complex's vast size, it was assigned its own ZIP code (10048).
The North Tower was destroyed during the terrorist attacks on September 11, 2001. It was the first tower to be hit, struck by American Airlines Flight 11 at 8:46 a.m., and it collapsed at 10:28 a.m., remaining standing for 102 minutes after impact. Of the total 2,977 casualties in these attacks, roughly 1,700 were inside or near this tower.
Its successor is the present-day One World Trade Center, which opened in November 2014 as the focal point of the rebuilt World Trade Center site. The northern reflecting pool at the National September 11 Memorial & Museum commemorates where the original tower once stood.
Development
In 1961, the Port Authority of New York and New Jersey committed to constructing the World Trade Center on the site formerly occupied by Hudson Terminal in Lower Manhattan. On , 1962, Minoru Yamasaki was appointed lead architect, with assistance from Emery Roth & Sons. Yamasaki’s initial concept featured twin towers with 80 stories each; however, to fulfill the Port Authority’s demand for of office space, each tower’s height was increased to 110 stories. The design revealed on , 1964 showcased a square floor plan measuring approximately per side.
Property acquisition began in March 1965, followed by demolition starting on , 1966. Groundbreaking took place on , 1966. Steel contracts worth $74 million were awarded in January 1967. Construction of the North Tower began in August 1968 and reached its full height by , 1970. Initial tenants occupied space as early as , 1970, prior to final completion. The official opening ceremony occurred on , 1973.
Operation
On February 13, 1975, a significant fire erupted on the North Tower’s 11th floor and spread to floors nine and fourteen. At that time, fire sprinkler systems had not been installed in the World Trade Center. Investigation identified a disgruntled custodian as responsible, who faced criminal charges. In response, a $45 million sprinkler installation project for the entire complex was announced by the Port Authority in 1981.
The first terrorist assault on the World Trade Center took place on February 26, 1993, when a Ryder truck packed with approximately 1,500 pounds of explosives detonated within the North Tower’s underground parking garage. The attackers intended to destabilize this tower and cause it to collapse onto the South Tower, aiming to bring down both structures. The blast resulted in six fatalities and injured over one thousand people. Structural repairs were necessary to restore support to affected floors.
In February 2001, management of the entire World Trade Center complex was leased by the Port Authority to Vornado Realty Trust. However, due to last-minute alterations requested by Vornado, Silverstein Properties—the next highest bidder—secured a lease agreement for the complex on July 24, 2001.
Destruction
At 8:46 a.m. Eastern Daylight Time on September 11, 2001, a group of five al-Qaeda hijackers deliberately flew American Airlines Flight 11 into the northern side of the North Tower, striking between the 93rd and 99th floors. Seventeen minutes later, at 9:03 a.m. EDT, another team of five terrorists crashed United Airlines Flight 175 into the South Tower, impacting floors 77 through 85.
The South Tower succumbed to collapse by 9:59 a.m., after enduring approximately 56 minutes of intense fire. The North Tower followed at 10:28 a.m., falling after burning for roughly 102 minutes due to structural failure. Falling debris from the North Tower caused extensive damage to 7 World Trade Center, igniting fires that weakened its framework and ultimately led to its collapse at 5:21 p.m.
In conjunction with these attacks, the Pentagon in Arlington, Virginia was also targeted, and United Airlines Flight 93 crashed in Pennsylvania after passengers attempted to regain control. These coordinated assaults resulted in the deaths of 2,996 individuals, including civilians, firefighters, law enforcement officers, military personnel, and hijackers. More than 90% of those who perished in the Twin Towers were located at or above the points of impact. In the North Tower, all three stairwells within the impact zone were destroyed by Flight 11’s collision, trapping approximately 1,355 people above that area who later died from smoke inhalation, falls, or during the collapse. While one stairwell in the South Tower remained intact after impact, escape was generally impossible for many occupants above the crash sites; additionally, 107 people below the impact zone in the North Tower also lost their lives.
Architecture
The Twin Towers were primarily designed by Minoru Yamasaki, with Emery Roth & Sons serving as associate architects. Structural engineers implemented preliminary versions of New York City's 1968 building code during the construction phase, integrating innovative approaches to building design. The towers utilized a tube-frame structural system, which reduced the amount of structural steel required by approximately 40% compared to traditional frameworks. Drawing inspiration from Le Corbusier and Yamasaki's signature gothic modernist aesthetic, the design also incorporated motifs from Islamic architecture, reflecting influences from Yamasaki’s earlier project on Saudi Arabia’s Dhahran International Airport in collaboration with the Saudi Binladin Group.
The North Tower stood at a height of , with a telecommunications antenna installed in 1979 and later upgraded in 1999 to support DTV broadcasting. Including this antenna, its tallest point reached . Both towers exceeded in height and each occupied around within the overall site area.
Facade
The exterior of the Twin Towers featured high-strength steel columns arranged around the perimeter, functioning as Vierendeel trusses. These closely spaced columns, despite their lightweight nature, created a robust and rigid outer wall. Each side of the buildings comprised 59 perimeter columns spaced at intervals of 3 ft 4 in, with walls measuring per side and corners that were beveled. The perimeter framework was assembled from prefabricated modular components connected by spandrel plates. From the seventh floor down to the foundation, column spacing increased to accommodate doorways. All columns were securely anchored into bedrock located between 65 and 85 feet (20–26 m) beneath ground level.
Structural features
Within the towers' cores were elevator shafts, utility rooms, restrooms, and three stairwells arranged within a rectangular footprint measuring 87 by 135 feet (27 by 41 m). The core structure included 47 steel columns extending continuously from bedrock to the roof and bore roughly half of each tower’s total weight. Except on mechanical floors, all elevators and stairwells were housed within this core. The open area between the core and perimeter was spanned by prefabricated floor trusses that connected to the perimeter columns.
Above the 107th floor, hat trusses provided support for communication antennas; however, only the North Tower had an antenna added in 1979. The framed-tube structural system combined steel core columns with perimeter columns coated in sprayed-on fireproofing material to create a lightweight but flexible framework capable of swaying under wind forces. Designer Leslie Robertson incorporated considerations for potential impacts from jet airliners during planning. Investigations by NIST revealed limited archival evidence regarding aircraft impact analyses at velocities up to .
Fire protection measures included sprayed fire-resistant materials (SFRMs), gypsum wallboard, and vermiculite coatings. Following a fire in 1975, additional fireproofing was applied; however, inspections after the 1993 bombing identified some deficiencies. Although New York City’s 1968 building codes did not mandate sprinkler systems for high-rise buildings except below ground level, sprinkler installations were retrofitted throughout the entire complex by 2001.
Tenants at the time of the attacks
The following tenant information is derived from an original list provided by CoStar Group, referenced by CNN, and compiled on UnBlinking.com. Cantor Fitzgerald maintained its corporate headquarters within 1 World Trade Center.
Note: Floor numbers highlighted in red denote areas impacted by American Airlines Flight 11 on September 11, 2001; floors trapped due to impact are marked with dark gray .
| Fl# | Companies | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 110/R | Local broadcast outlets including Channel 2 (WCBS), Channel 4 (WNBC), Channel 5 (WNYW), Channel 7 (WABC), Channel 9 (WWOR), Channel 11 (WPIX), Channel 13 (WNET), Channel 31 (WPXN), Channel 47 (WNJU), radio stations such as WKCR-FM, WPAT-FM, WNYC-FM, WKTU-FM, along with CNBC, Genuity, and CNN | |||||||||||||||||||||
| 109 | Mechanical floor | |||||||||||||||||||||
| 108 | Mechanical floor | |||||||||||||||||||||
| 107 | Windows on the World, including Greatest Bar on Earth and Wild Blue | |||||||||||||||||||||
| 106 | Windows on the World, Wine School, Conference and Banquet facilities | |||||||||||||||||||||
| 105 | Cantor Fitzgerald, eSpeed, Genuity | |||||||||||||||||||||
| 104 | Cantor Fitzgerald, eSpeed, WNBC Channel 4, UmeVoice | |||||||||||||||||||||
| 103 | Cantor Fitzgerald, eSpeed | |||||||||||||||||||||
| 102 | Cantor Fitzgerald, Alliance Consulting Group, The Nishi-Nippon Bank Limited, PaineWebber, Kidder Peabody & Co. | |||||||||||||||||||||
| 101 | Cantor Fitzgerald, eSpeed, Boomer Esiason Foundation, Chances for Children charity, Kidder Peabody & Co. | |||||||||||||||||||||
| 100 | Marsh & McLennan Companies | |||||||||||||||||||||
| 99 | Marsh & McLennan Companies | |||||||||||||||||||||
| 98 | Marsh & McLennan Companies | |||||||||||||||||||||
| 97 | Marsh & McLennan Companies | |||||||||||||||||||||
| 96 | Marsh & McLennan Companies, Sumitomo Mitsui Banking Corporation | |||||||||||||||||||||
| 95 | Marsh & McLennan Companies | |||||||||||||||||||||
| 94 | Marsh & McLennan Companies, Marsh Private Client Services, Guy Carpenter | |||||||||||||||||||||
| 93 | Marsh & McLennan Companies, Fred Alger Management, Castle Convertible Fund Inc. | |||||||||||||||||||||
| 92 | Carr Futures; Lower Manhattan Cultural Council Art Program and Open Studios | |||||||||||||||||||||
| 91 | American Bureau of Shipping; Cedel Bank International; Meyers Pollok Robbins; New Japan Securities International; Shiga Bank; LMCC Art Program and Open Studios | |||||||||||||||||||||
| 90 | American TCC International Group; Chugoku Bank; Dun & Bradstreet; Clearstream International; Pass Consulting Corporation | |||||||||||||||||||||
| 89 | Barcley Dwyer; Bayview Services LLC; CIIC Group (US); Cosmos Services America; Daehan International (Hana Financial Group); Drinker Biddle & Reath; MetLife; Mutual International Forwarding; Strategic Communications Group; Wai Gao Qiao USA; Wall Street Planning Association; Banco LatinoAmericano de Exportaciones Sud America; Italian Wine & Food Institute; Majestic Star Yacht Chartering; Tokyo Securities Company | |||||||||||||||||||||
| 88 | Viking Sea Freight; WTC Construction Manager | |||||||||||||||||||||
| 87 | May Davis Group; Bank of Kinki; Thor Technologies | |||||||||||||||||||||
| 86 | Julien J. Studley (Studley Inc.); Asiatic Chemical; Society of Satellite Professionals International | |||||||||||||||||||||
| 85 | SMW Trading Corporation; Thermo Electron; Chicago Investment Group; Hyakugo Bank; Ohrenstein & Brown | |||||||||||||||||||||
| 84 | Bright China Capital; David Peterson Law Offices; LG Securities America (later merged with NH Investment & Securities and KB Securities); San-In Godo International Bank; Temenos USA Wholesalers; Unicom Capital Advisors; Blue Star Line North America; Daehan International (Hana Financial Group) | |||||||||||||||||||||
| 83 | Axcelera; General Telecommunications; eMeritus Communications; Lava Trading LLC; Global Crossings Holdings; Ameson Education and Culture Exchange Foundation; Taipei Bank; Toho Bank; Wako Securities America | |||||||||||||||||||||
| 82 | New York Metropolitan Transportation Council; DMJM Harris | |||||||||||||||||||||
| 81 | Bank of America; Blue Star Line North America; Network Plus; New Continental Enterprises | |||||||||||||||||||||
| 80 | Agricor Commodities Corporation; Intrust Investment Realty; Noga Commodities Overseas and Noga Hotels New York subsidiaries; Shizuoka Bank; RLI Insurance Company; Bank of Yokohama; Zenshinren Bank | |||||||||||||||||||||
| 79 | Daynard & Van Thunen Company; First Liberty Investment Group; Nikko Securities; Okato Shoji Company International; Securant Technologies; Iyo Bank; Symphoni Interactive LLC | |||||||||||||||||||||
| 78 | 'Skylobby'; Avenir Capital Management Associates along with various international trade organizations including Hyundai Motor Company and Partner Reinsurance Company | |||||||||||||||||||||
| 77 | 'Hal Roth Agency'; Jun He Law Offices plus other multinational firms such as Kuhne & Nagel and Partner Reinsurance Company | |||||||||||||||||||||
| Mechanical floor |- style="background:#999;" | Mechanical floor |- | Morgan Stanley |- | Port Authority of New York & New Jersey and Morgan Stanley |- | Morgan Stanley |- | Morgan Stanley |- | Morgan Stanley |- | Morgan Stanley |- | Morgan Stanley |- | Port Authority of New York & New Jersey |- | Port Authority of New York & New Jersey |- | Boeing Aviation Technical Services and Morgan Stanley |- | Port Authority of New York & New Jersey and Morgan Stanley |- | Morgan Stanley and Airport Access Program |- | Morgan Stanley |- | Morgan Stanley |- | Asahi Bank (Resona Holdings) |- | Sidley Austin Brown & Wood law firm |- | Pace University including its World Trade Institute and Downtown Conference Center |- | Sidley Austin Brown & Wood law firm |- | AIG Aviation Brokerage ; Bank of Taiwan ; Bramax Manufacturing Corporation ; China Resource Products USA ; Keenan Powers & Andrews ; LoCurto & Funk Inc. ; National Nydegger Transport Corporation ; Pacrim Trading & Shipping ; Pure Energy Corporation ; Broadview Networks ; French Embassy Financial Services ; JACOM Corporation ; TripleHop Technologies |- | Gayer Shyu & Wiesel ; Hill Betts & Nash ; Howly US Corporation ; Leeds & Morrelli ; Okasan Securities ; RGL Gallagher PC ; Williams Capital Group ; Bramax Manufacturing Corporation ; Temenos USA Wholesalers ; Unifacemanu International |- | AT&T Corporation ; C&P Press ; Chilean Government Trade Bureau along with various Chilean trade organizations including Tradeweb |-
... [List continues with additional tenants across floors] ... |
SOURCES: CoStar Group, CNN, Unblinking
Tenants with unknown floor locations include Alliance Global Finance alongside multiple international trading and shipping firms.
92nd floor
Located immediately beneath the point of impact from Flight 11, the 92nd floor had no survivors. On the morning of the attack, sixty-nine individuals were present, including sixty-seven staff members from Carr Futures, a tenant occupying this level. While the structural integrity of the floor remained intact, it suffered significant nonstructural damage—walls collapsed, windows shattered, electrical wiring was severed, and flooding reached knee height due to ruptured water pipes. Although the stairwells themselves were undamaged, debris from the upper impact obstructed access, and elevator operations ceased above the 50th floor, effectively trapping occupants on the 92nd floor without viable escape routes.[1]
At first, conditions mirrored those on the 91st floor, where all occupants managed to evacuate safely. However, aviation fuel leaked onto the 92nd floor and ignited fires that quickly spread along its eastern section. Within twelve minutes, eight employees perished after jumping to avoid the advancing flames. Survivors initially gathered on the western side of the floor, which was free from smoke and fire at that time; yet, as the blaze extended westward, survival became impossible.[2]
The last known communication from the North Tower came from Thomas McGinnis, a trader trapped with others inside a congested conference room after structural failure caused the building to buckle. By 10:18 a.m., flames had consumed much of the floor, leaving little room to evade them. Despite his wife's attempts at reassurance over the phone, McGinnis expressed skepticism about surviving as he observed people jumping from higher floors. His call concluded at 10:26 a.m., just two minutes prior to the tower’s collapse.[1]
Tenants that left prior to the attacks
From 1978 until 1995, Suite 1609 in 1 World Trade Center was home to the Consulate of Paraguay. Meanwhile, Home Lines occupied Suite 3969 between 1974 and 1988.
External links
- "WTC Response Update: Governor Pataki Announces Partnership To Help New York City Businesses In Need Of Office Space". CoStar Group.
- List of World Trade Center tenants via CNN (Archive)
- World Trade Center Tenant Relocation Summary via TenantWise.com
- World Trade Center Tragedy: Information for Families, Friends and Colleagues – Marsh and McLennan Companies