A complex of seven buildings on 16-acres, constructed and operated by the Port Authority of New York and New Jersey.  Seven underground levels included services, shopping, train and subway stations.  Complex had more than 10,000,000 square feet of rentable space, occupied by about 50,000 people.

Minoru Yamasaki

Groundbreaking: August 5th, 1966.  Steel construction began in August,

1968. First tenant occupancy of One WTC was December, 1970, and occupancy of Two WTC began in January 1972.  Ribbon cutting was on April 4, 1973. Demolished by terrorist attack on September 11, 2001.

110 floors each.  Tower One was 1368 feet tall and Tower Two was 1362 feet.  Each tower was 208 feet wide.  The upper floors had as much as 40,000 square feet of office space per floor.   Gross area of 43,200 square feet each per floor.  There were no interior columns.  The towers operated with combined express/local elevator banks called a sky lobby system.  The buildings had three vertical zones; express elevators served sky lobbies at the 41^st and 72^nd floors.  From these, and from the plaza level, four banks of local elevators carried passengers to each of the three zones.  About 99 elevators per building.

One World Trade Center

Four World Trade Center

One Liberty Plaza