List of tallest buildings and structures
The world's tallest artificial structure is the Burj Khalifa in Dubai (of the United Arab Emirates). The building gained the official title of "Tallest Building in the World" and the tallest self-supported structure at its opening on January 9, 2010. The second-tallest self-supporting structure and the tallest tower is the Tokyo Skytree. The tallest guyed structure is the KVLY-TV mast.
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.