7 World Trade Center
The original 7 World Trade Center from the WTC observation deck in August 1992
Interactive map of 7 World Trade Center
Alternative names	WTC 7 7 WTC Building 7 Tower 7 Salomon Brothers Building
General information
Status	Destroyed
Type	Office
Location	250Greenwich Street Manhattan,New York City 10006, United States
Coordinates	40°42′48″N74°00′43″W / 40.7133°N 74.0119°W /40.7133; -74.0119
Construction started	October 2, 1984
Completed	March 1987
Opened	May 1987
Destroyed	September 11, 2001
Height
Architectural	610 ft (190 m)
Technical details
Floor count	47
Floor area	2,000,000 sq ft (190,000 m2)
Lifts/elevators	32
Design and construction
Architect	Emery Roth & Sons
Developer	Silverstein Properties
Structural engineer	Irwin Cantor
Main contractor	Tishman Construction

7 World Trade Center (7 WTC,WTC-7, orTower 7), colloquially known asBuilding 7 or theSalomon Brothers Building, was an office building constructed as part of the originalWorld Trade Center Complex inLower Manhattan,New York City. The tower was located on a city block bounded byWest Broadway,Vesey Street,Washington Street, and Barclay Street on the east, south, west, and north, respectively. It was developed byLarry Silverstein, who held aground lease for the site from thePort Authority of New York and New Jersey, and designed byEmery Roth & Sons. It was destroyed during theSeptember 11 attacks due to structural damage caused by fires. It experienced a period of almost free-fall, total collapse acceleration lasting approximately 2.25 seconds during its 5.4-second collapse, as acknowledged in theNIST final report.^[1]

The original7 World Trade Center was47 stories tall, clad in red granite masonry, and occupied atrapezoidal footprint. An elevated walkway spanning Vesey Street connected the building to the World Trade Center plaza. The building was situated above aConsolidated Edison power substation, which imposed unique structural design constraints. The building opened in 1987, andSalomon Brothers signed a long-term lease the next year, becoming the anchor tenant of7 WTC.

On September 11, 2001, the structure was substantially damaged by debris when the nearbyNorth Tower (1 World Trade Center)collapsed. The debris ignited fires on multiple lower floors of the building, which continued to burn uncontrolled throughout the afternoon. The building's internal fire suppression system lacked water pressure to fight the fires. 7 WTC began to collapse when a critical internal columnbuckled and triggeredcascading failure of nearby columns throughout, which were first visible from the exterior with the crumbling of a rooftop penthouse structure at 5:20:33 pm. This initiated theprogressive collapse of the entire building at5:21:10 pm, according toFEMA,^[2]: 23 while the 2008 NIST study placed the final collapse time at5:20:52 pm.^{[3]: 19, 21, 50–51} The collapse made the old 7 World Trade Center the first steel skyscraper known to have collapsed primarily due to uncontrolled fires.^[4][5]A new building on the site opened in 2006.

The original 7 World Trade Center was a 47-story building, designed byEmery Roth & Sons, with a redgranite facade. The building was 610 feet (190 m) tall, with atrapezoidal footprint that was 330 ft (100 m) long and 140 ft (43 m) wide.^[6][7]Tishman Realty & Construction managed construction of the building.^[6]

7 World Trade Center was constructed above a two-storyCon Edisonsubstation that had been located on the site since 1967.^[8][9] The substation had acaisson foundation designed to carry the weight of a future building of 25 stories containing 600,000 sq ft (56,000 m²).^[10] However, the final design for 7 World Trade Center was for a much larger building than originally planned when the substation was built.^{[11]: xxxviii} The structural design of 7 World Trade Center therefore included a system of gravity column transfertrusses and girders, located between floors 5 and 7, to transfer loads to the smaller foundation.^[3]: 5 Existing caissons installed in 1967 were used, along with new ones, to accommodate the building. The 5th floor functioned as a structural diaphragm, providing lateral stability and the distribution of loads between the new and old caissons. Above the 7th floor, the building's structure was a typicaltube-frame design, with columns in the core and on the perimeter, and lateral loads resisted by perimeter moment frames.^[10]

A shipping and receiving ramp, which served the entire World Trade Center complex, occupied the eastern quarter of the 7 World Trade Center footprint. The building was open below the 3rd floor, providing space for truck clearance on the shipping ramp.^[10] The spray-onfireproofing for structural steel elements wasgypsum-basedMonokote, which had a two-hour fire rating for steel beams, girders, and trusses, and a three-hour rating for columns.^[2]: 11

Mechanical equipment was installed on floors four through seven, including 12 transformers on the 5th floor. Severalemergency generators installed in the building were used by theNew York City Office of Emergency Management,Salomon Smith Barney, and other tenants.^[2]: 13 In order to supply the generators, 24,000 gallons (91,000 L) ofdiesel fuel were stored below ground level.^[12] Diesel fuel distribution components were located at ground level, up to the ninth floor.^[13]: 35 The roof of the building included a small west penthouse and a larger east mechanical penthouse.^[8]

Each floor had 47,000 sq ft (4,400 m²) of rentable office space, which made the building's floor plans considerably larger than most office buildings in the city.^[14] In all, 7 World Trade Center had 1,868,000 sq ft (173,500 m²) of office space.^[2]: 1 Two pedestrian bridges connected the main World Trade Center complex, across Vesey Street, to the third floor of 7 World Trade Center. In addition to several acquired artworks, from artists such asFrank Stella,Roy Lichtenstein, andRoss Bleckner, the lobby of 7 World Trade Center housed a large mural by artistAl Held, titledThe Third Circle.^[15]

The groundbreaking ceremony was hosted on October 2, 1984.^[9] The building opened in May 1987 as part of theWorld Trade Center.^[16]

In June 1986, before construction was completed, developerLarry Silverstein signedDrexel Burnham Lambert as a tenant to lease the entire 7 World Trade Center building for $3 billion over a term of 30 years.^[17]In December 1986, after theBoeskyinsider-trading scandal, Drexel Burnham Lambert canceled the lease, leaving Silverstein to find other tenants.^[18]Spicer & Oppenheim agreed to lease 14 percent of the space, but for more than a year, asBlack Monday and other factors adversely affected theLower Manhattan real estate market, Silverstein was unable to find tenants for the remaining space. By April 1988, he had lowered the rent and made other concessions.^[19]

In November 1988, Salomon Brothers withdrew from plans to build a large new complex atColumbus Circle inMidtown, instead agreeing to a 20-year lease for the top 19 floors of 7 World Trade Center.^[20] The building was extensively renovated in 1989 to accommodate Salomon Brothers, and 7 World Trade Center alternatively became known as the Salomon Brothers building.^[21] Most of the three existing floors were removed as tenants continued to occupy other stories, and more than 350 tons (U.S.) of steel were added to construct three double-height trading floors. Nine diesel generators were installed on the 5th floor as part of a backup power station. "Essentially, Salomon is constructing a building within a building – and it's an occupied building, which complicates the situation", said a district manager ofSilverstein Properties.^[21] According to Larry Silverstein, the unusual task was possible because it could allow "entire portions of floors to be removed without affecting the building's structural integrity, on the assumption that someone might need double-height floors."^[21]

After theWorld Trade Center bombing of February 26, 1993, New York City mayorRudy Giuliani decided to situate the emergency command center and associated fuel tanks at 7 World Trade Center. Although this decision was criticized in light of the events of9/11, the fuel in the building is not believed to have contributed to the collapse of the building.^{[22][23]: 2}

At the time of the September 11 attacks, Salomon Smith Barney was by far the largest tenant in 7 World Trade Center, occupying 1,202,900 sq ft (111,750 m²) (64 percent of the building) which included floors 28–45.^{[2]: 2 [24]} Other major tenants includedITT Hartford Insurance Group (122,590 sq ft/11,400 m²),American Express Bank International (106,117 sq ft/9,900 m²),Standard Chartered Bank (111,398 sq ft/10,350 m²), and theSecurities and Exchange Commission (106,117 sq ft/9,850 m²).^[24] Smaller tenants included theInternal Revenue Service Regional Council (90,430 sq ft/8,400 m²) and theUnited States Secret Service (85,343 sq ft/7,900 m²).^[24] The smallest tenants included theNew York City Office of Emergency Management,^[25]National Association of Insurance Commissioners,Federal Home Loan Bank of New York, First State Management Group Inc.,Provident Financial Management, and theImmigration and Naturalization Service.^[24] TheDepartment of Defense (DOD) andCentral Intelligence Agency (CIA) shared the 25th floor with the IRS.^[2]: 2 (The clandestine CIA office was revealed only after the 9/11 attacks.)^[26] Floors 46–47 weremechanical floors, as were the bottom six floors and part of the seventh floor.^{[2]: 2 [26]}

According toCoStar Group, floors 9 and 10 of 7 WTC were occupied by the Secret Service.^[27] The CIA had offices on the 25th floor of 7 WTC, as reported by theAssociated Press.^[28] TheNational Institute of Standards and Technology's 2008Final Report on the Collapse of World Trade Center Building 7 confirmed that floor 14 was vacant, and updated the news reports of CoStar and Associated Press from 2001 to show that Salomon Smith Barney leased floors 15 to 17.^[29]: 9

The total amount of space occupied by each tenant was:^{[29]: 9 [27][30]}

Collapse of 7 World Trade Center
Part ofSeptember 11 attacks andCollapse of the World Trade Center
The building on fire, prior to the collapse, as seen fromBrookfield Place
Interactive map of Collapse of 7 World Trade Center
Location	7 World Trade Center
Date	September 11, 2001 5:21 pm (Eastern Daylight Time)
Target	Civilians
Attack type	Building collapse
Deaths	0
Injured	Unknown

As the North Tower (1 World Trade Center) collapsed on September 11, 2001, heavy debris hit 7 World Trade Center, damaging the south face of the building^{[31]: 18 (PDF p. 22)} and starting fires that continued to burn throughout the afternoon.^{[3]: 16, 18} The collapse also caused damage to the southwest corner between floors 7 and 17 and on the south face between floor 44 and the roof; other possible structural damage included a large vertical gash near the center of the south face between floors 24 and 41.^[3]: 17 The building was equipped with asprinkler system, but had many single-point vulnerabilities for failure: the sprinkler system required manual initiation of the electrical fire pumps instead of being a fully automatic system; the floor-level controls had a single connection to the sprinkler water riser, and the sprinkler system required some power for thefire pump to deliver water.^[32]: 11 Additionally, water pressure was low, with little or no water to feed sprinklers.^{[33]: 23–30}

After the North Tower collapsed, some firefighters entered 7 World Trade Center to search the building. They attempted to extinguish small pockets of fire, but low water pressure hindered their efforts.^[34] Over the course of the day, fires burned out of control on several floors of 7 World Trade Center, the flames visible on the east side of the building.^[35] During the afternoon, the fire was also seen on floors 6–10, 13–14, 19–22, and 29–30.^{[31]: 24 (PDF p. 28)} In particular, the fires on floors 7 through 9 and 11 through 13 continued to burn out of control during the afternoon.^[4] At approximately 2:00 pm, firefighters noticed a bulge in the southwest corner of 7 World Trade Center between the 10th and 13th floors, a sign that the building was unstable and might collapse.^[36] During the afternoon, firefighters also heard creaking sounds coming from the building.^[37] Around 4:00 pm, FDNY Chief of OperationsDaniel A. Nigro decided to halt rescue operations and evacuate the immediate area due to concerns for the safety of personnel.^[38]

The fire expanded the girders of the building, causing some to collapse. This led to the northeast corner core column (Column 79), which was especially large, to buckle below the 13th floor. This caused the floors above it to collapse to the transfer floor at the fifth level. The structure also developed cracks in the facade just before the entire building started to fall.^{[3]: 21 [39]} According to FEMA, this collapse started at 5:20:33 pm EDT when the east mechanical penthouse started crumbling.^{[2]: 23 [40]} Differing times are given as to what time the building completely collapsed:^[40] at 5:21:10 pm EDT according to FEMA,^[2]: 23 and at 5:20:52 pm EDT according to NIST.^{[3]: 19, 21, 50–51}

There were nocasualties associated with the collapse.^[39] NIST found no evidence to supportconspiracy theories such as the collapse being the result of explosives; it found that a combination of factors including physical damage, fire, and the building's unusual construction set off a chain-reaction collapse.^[41][42]

In May 2002, theFederal Emergency Management Agency (FEMA) issued a report on the collapse based on a preliminary investigation conducted jointly with the Structural Engineering Institute of theAmerican Society of Civil Engineers under the leadership of Dr.W. Gene Corley, P.E. FEMA made preliminary findings that the collapse was not primarily caused by actual impact damage from the collapse of 1 WTC and 2 WTC but by fires on multiple stories ignited by debris from the other two towers that continued burning unabated due to lack of water for sprinklers or manual firefighting. The report did not reach conclusions about the cause of the collapse and called for further investigation.^[23]: 3

Subsequently, theNational Institute of Standards and Technology (NIST)was authorized to lead an investigation into the structural failure andcollapse of the World Trade Center Twin Towers and 7 World Trade Center.^[4] The investigation, led by Dr S. Shyam Sunder, drew upon in-house technical expertise as well as the knowledge of several outside private institutions, including the Structural Engineering Institute of theAmerican Society of Civil Engineers (SEI/ASCE); theSociety of Fire Protection Engineers (SFPE); theNational Fire Protection Association (NFPA); the American Institute of Steel Construction (AISC); theCouncil on Tall Buildings and Urban Habitat (CTBUH); and theStructural Engineers Association of New York (SEAoNY).^[43]

The bulk of the investigation of 7 World Trade Center was delayed until after reports were completed on the Twin Towers.^[4] In the meantime, NIST provided a preliminary report about 7 WTC in June 2004, and thereafter released occasional updates on the investigation.^[31] According to NIST, the investigation of 7 World Trade Center was delayed for a number of reasons, including that NIST staff who had been working on 7 World Trade Center were assigned full-time from June 2004 to September 2005 to work on the investigation of the collapse of the Twin Towers.^[44] In June 2007, Shyam Sunder explained,

We are proceeding as quickly as possible while rigorously testing and evaluating a wide range of scenarios to reach the most definitive conclusion possible. The 7 WTC investigation is in some respects just as challenging, if not more so than the study of the towers. However, the current study does benefit greatly from the significant technological advances achieved and lessons learned from our work on the towers.^[45]

In November 2008, NIST released its final report on the causes of the collapse of 7 World Trade Center.^[3] This followed NIST's August 21, 2008, draft report, which included a period for public comments,^[4] and was followed in 2012 by a peer-reviewed summary in theJournal of Structural Engineering.^[46] In its investigation, NIST utilizedANSYS to model events leading up to collapse initiation andLS-DYNA models to simulate the global response to the initiating events.^{[47]: 6–7} NIST determined that diesel fuel did not play an important role, nor did the structural damage from the collapse of the Twin Towers or the transfer elements (trusses, girders, and cantilever overhangs). The lack of water to fight the fire was an important factor. The fires burned out of control during the afternoon, causing floor beams near column 79 to expand and push a key girder off its seat, triggering the floors to fail around column 79 on floors 8 to 14. With a loss of lateral support across nine floors, column 79 buckled – pulling the east penthouse and nearby columns down with it. With the buckling of these critical columns, the collapse then progressed east-to-west across the core, ultimately overloading the perimeter support, which buckled between Floors 7 and 17, causing the remaining portion of the building above to fall down as a single unit. The fires, which were fueled by office contents and burned for 7 hours, along with the lack of water, were the key reason for the collapse.^{[3]: 21–22} At the time, this made the old 7 WTC the only steel skyscraper to have collapsed from fire; subsequently there have been others, including theEdifício Wilton Paes de Almeida, thePlasco Building, and theWindsor Tower.^[5]

Files relating to numerous federal investigations had been housed at 7 World Trade Center. TheEqual Employment Opportunity Commission estimated over 10,000 of its cases were affected.^[48] Investigative files in the Secret Service's largest field office were lost, with one Secret Service agent saying, "All the evidence that we stored at 7 World Trade, in all our cases, went down with the building."^[49] Copies of emails in connection with theWorldCom scandal that were later requested by theSEC fromSalomon Brothers, a subsidiary ofCitigroup housed in the building, were also destroyed.^[50]

The NIST report found no evidence supporting the conspiracy theories that 7 World Trade Center was brought down by controlled demolition. Specifically, the window breakage pattern and blast sounds that would have resulted from the use of explosives were not observed.^{[3]: 26–28} The suggestion that an incendiary material such asthermite was used instead of explosives was considered unlikely by NIST because of the building's structural response to the fire, the nature of the fire, and the unlikelihood that a sufficient amount of thermite could be planted without discovery.^[4] Based on its investigation, NIST reiterated several recommendations it had made in its earlier report on the collapse of the Twin Towers.^{[3]: 63–73} It urged immediate action on a further recommendation: that fire resistance should be evaluated under the assumption that sprinklers are unavailable;^{[3]: 65–66} and that the effects of thermal expansion on floor support systems be considered.^{[3]: 65, 69} Recognizing that current building codes are drawn to prevent loss of life rather than building collapse, the main point of NIST's recommendations was that buildings should not collapse from fire even if sprinklers are unavailable.^{[3]: 63–73}

The collapse of 7 WTC sent debris flying into the nearbyBorough of Manhattan Community College'sFiterman Hall building, located at 30 West Broadway, damaging and contaminating it beyond repair.^[51] A revised plan called for demolition in 2009 and completion of the new Fiterman Hall in 2012, at a cost of $325 million.^[52] The collapse also damaged the eastern facade of theBarclay–Vesey Building, anArt Deco building to the west; it was restored at a cost of US$1.4 billion.^[53] Construction on the new7 World Trade Center began in 2002,^[54] and the new structure opened in 2006.^[55]

• 
  The southeast corner of the building
• 
  Heavy fire showing from WTC 7's eastern side
• 
  Fire visible on WTC 7's north face
• 
  WTC 7 burning behind the Barclay–Vesey Building
• 
  WTC 7's rubble

• List of tallest buildings in New York City
• World Trade Center in popular culture

Wikimedia Commons has media related to7 World Trade Center (1987).

• 7 World Trade Center at SilversteinProperties.com
• 7 World Trade Center onCTBUH Skyscraper Center

• 1987 establishments in New York City
• Buildings and structures destroyed in the September 11 attacks
• Emery Roth buildings
• Office buildings completed in 1987
• Skyscraper office buildings in Manhattan
• World Trade Center

• Pages using gadget WikiMiniAtlas
• CS1: unfit URL
• Articles with short description
• Short description is different from Wikidata
• Use American English from April 2025
• All Wikipedia articles written in American English
• Use mdy dates from April 2025
• Pages using infobox mapframe without shape links in Wikidata
• Coordinates on Wikidata
• Commons category link from Wikidata
• Pages using New York City Subway service templates
• Pages using the Kartographer extension