List of tallest buildings
The international non-profit organization Council on Tall Buildings and Urban Habitat (CTBUH) was formed in 1969 and announces the title of "The World's Tallest Building" and sets the standards by which buildings are measured. It maintains a list of the 100 tallest completed buildings in the world. The organization currently ranks Burj Khalifa in Dubai as the tallest at . The CTBUH only recognizes buildings that are complete however, and some buildings included within the lists in this article are not considered finished by the CTBUH.
Empire State Building
With the destruction of the World Trade Center in the September 11 attacks in 2001, the Empire State Building again became the tallest building in New York City, but was only the second-tallest building in the Americas after the Willis Tower in Chicago. As a result of the attacks, transmissions from nearly all of the city's commercial television and FM radio stations were again broadcast from the Empire State Building. The attacks also led to an increase in security due to persistent terror threats against New York City landmarks.