The “Twin Towers” of the World Trade Center officially opened in
New York City after years of delays. The buildings replaced the
Empire State Building as the world’s tallest building. Though they
would only hold that title for a year, they remained a dominant
feature of the city’s skyline and were recognizable the world over
long before they were destroyed in a terrorist attack in 2001. 

Manhattan in 1973.

Sept. 19, 2001: Smoke rises from ground zero of the
collapsed World Trade Center, more than a week after
the terrorist attacks in New York. (AP)

Today, the One World Trade Center in Lower Manhattan. A 
height of 1,776 feet includes its spire.