Snapshots--By the Numbers

The human toll, and World Trade Center facts and figures

3 min read

  • 11 September–The Human Toll
  • World Trade Center Facts and Figures
  • Status of WTC Technology Companies

11 September—The Human Toll

Totals of dead and missing in attacks, as of October 17, 2001:

New York City:
World Trade Center: 4613 missing; 3456 confirmed dead

  • 80 nationalities represented in the dead and missing toll, according to U.S. Secretary of State Colin Powell
  • The New York Fire Department lost 343 people in its 11 400-member force; one out of every 33 people on the force

Those on hijacked planes:

  • American Flight 11: 92
  • United Flight 175: 65

Washington, D.C.:
Pentagon: 189 killed:

  • American Flight 77, which hit the Pentagon: 64 dead
  • United Flight 93, believed to be bound for Washington: 44 killed in Pennsylvania crash

Sources: Associated Press, National Public Radio, Times of London, New York Times

World Trade Center–Facts and Figures

Consisted of seven buildings

Architects: Minoru Yamasaki & Associates; Emery Roth & Sons–for Port Authority of New York and New Jersey

Main plot occupied by five of the buildings: 293 m by 216 m (63 268 m2)


917 466 cubic meters of earth excavated

181 436 960 kg of steel used

324 936 cubic meters of concrete used

3500 workers daily during peak periods of construction

43 600 windows–55 742 m2 of glass window area in the Twin Towers

Largest refrigeration plant in the world–54 431 088 kg of cooling capacity

110-m television mast atop 1 World Trade Center supported 10 main television antennas and a master FM antenna

1 World Trade Center — North Tower

  • Built 1970
  • Height: 417 m–110 floors
  • Floor sizes (9—105) 4181—4645 m2
  • Elevators: 97 passenger, 6 freight

2 World Trade Center–South Tower

  • Built 1972
  • Height: 415 m–110 floors
  • Floor sizes (2—109 )4181—4645 m2
  • Elevators: 97 passenger, 6 freightv Notable Comments:

Minoru Yamasaki, chief architect:

"World trade means world peace and consequently, the World Trade Center buildings…had a bigger purpose than just to provide room for tenants. The World Trade Center is a living symbol of man’s dedication to world peace."

Austin Tobin, the head of the Port Authority, who commissioned the Center:

"[The towers are] the first buildings of the twenty-first century."

Status of WTC Technology Companies

Company Tower Floor What Firm Does Employees at WTC Status of Employees and Business
America Bright SignsNorth33Computer services3All escaped safely. Employees are working out of the French embassy in NYC.
AT&TNorth51Telecom8 to 10Reports no damage to network; All employees escaped.
BaselineSouth77-78Software175Four employees are still missing.
Broadview NetworksNorth53Telecom10All employees accounted for.
Channel 11 (WPIX)North110Television1One technician monitoring the transmitter is missing. Channel is broadcasting by backup antenna at Empire State Building and via cable.
Channel 2 (WCBS)North110Television2Two technicians at transmitter are missing. Channel is broadcasting from backup antenna on Empire State Building.
Channel 31 (WBIS)North110TelevisionUnmanned technical stationAll employees survived.
Channel 4 (WNBC)North104TelevisionUnmanned technical stationAll employees survived.
Channel 47 (WNJU)North110TelevisionUnmanned technical stationAll employees survived.
Channel 5 (WNYW)North110TelevisionUnmanned technical stationAll employees survived.
Communications Workers of AmericaN/AN/ATelecom216Known casualties included five Verizon workers (two of whom were at the Pentagon); one worker at each of the television networks, NBC and ABC; four Port Authority workers; one retired member who perished aboard an airliner used in the terrorist attack. 204 members remain unaccounted for.
Dahao USANorth46Software4All employees survived.
General TelecomNorth83Telecom37Thirteen employees are missing. Company has moved to new offices on W. 22nd St. in Manhattan.
GenuityNorth105Tech10Three technicians working on the 105th floor were last heard heading for the roof of the building. They are missing.
IQ Financial SystemsSouth83Software110All but four employees are accounted for and safe. Business will resume shortly.
Kanebo Information Systems Corp., U ComputersNorth46Computer services4Three employees and one temp escaped safely, but company cannot locate or contact them now.
Martin progressive L.L.C. ComputerNorth77Computer services80All safe.
Meganet Management ConsultingNorth46Computing All employees evacuated safely.
MRV CommunicationsN/AN/ANetworkingN/AEdmund Glazer, 41, CFO, was killed in one of the hijacked planes.
Network PlusNorth81Telecom51All safe.
Quantum/ATLNorth78Data Storage4All employees are safe. Business is running with employees working remotely.
Raytheon    Four employees, passengers on flights that crashed into the World Trade Center and Pentagon, died.
SunGardSouth58e-Commerce8All WTC workers are safe. Of about 20 other employees visiting clients, three are missing. Supporting customers from sites in Chicago and on the West Coast.
The Beast.comNorth80Computer services All employees are reported safe.
Thermo ElectronNorth85Biomedical Devices9Three workers were on site at time of attack. All escaped
Tianli  Electrical Machinery Could not be reached.
Trading TechnologiesNorth86Software7All seven employees are safe.
UnisysN/AN/AComputer services150All service personnel in WTC accounted for and safe.
Verizon CommunicationsSouth9-12Telecom500Six employees are missing. Collapse sent steel beams crashing through a nearby Verizon Facility, cause outages of some 200,000 telephone lines.

This article is for IEEE members only. Join IEEE to access our full archive.

Join the world’s largest professional organization devoted to engineering and applied sciences and get access to all of Spectrum’s articles, podcasts, and special reports. Learn more →

If you're already an IEEE member, please sign in to continue reading.

Membership includes:

  • Get unlimited access to IEEE Spectrum content
  • Follow your favorite topics to create a personalized feed of IEEE Spectrum content
  • Save Spectrum articles to read later
  • Network with other technology professionals
  • Establish a professional profile
  • Create a group to share and collaborate on projects
  • Discover IEEE events and activities
  • Join and participate in discussions