CN Tower
"Guinness World Records" has called the CN Tower "the world's tallest self-supporting tower" and "the world's tallest free-standing tower". Although Guinness did list this description of the CN Tower under the heading "tallest building" at least once, it has also listed it under "tallest tower", omitting it from its list of "tallest buildings." In 1996, Guinness changed the tower's classification to "World's Tallest Building and Freestanding Structure". Emporis and the Council on Tall Buildings and Urban Habitat both listed the CN Tower as the world's tallest free-standing structure on land, and specifically state that the CN Tower is not a true building, thereby awarding the title of world's tallest building to Taipei 101, which is shorter than the CN Tower. The issue of what was tallest became moot when Burj Khalifa, then under construction, exceeded the height of the CN Tower in 2007 (see below).
U.S. Bank Tower (Los Angeles)
U.S. Bank Tower, formerly Library Tower and First Interstate Bank World Center, is a skyscraper at 633 West Fifth Street in downtown Los Angeles, California, United States. It is the third-tallest building in California, the second-tallest building in Los Angeles, the fifteenth-tallest in the United States, the third-tallest west of the Mississippi River after the Salesforce Tower and the Wilshire Grand Center, and the 92nd-tallest building in the world, after being surpassed by the Wilshire Grand Center. Because local building codes required all high-rise buildings to have a helipad, it was known as the tallest building in the world with a roof-top heliport from its completion in 1989 to 2010 when the China World Trade Center Tower III opened. It is also the third-tallest building in a major active seismic region; its structure was designed to resist an earthquake of 8.3 on the Richter scale. It consists of 73 stories above ground and two parking levels below ground. Construction began in 1987 with completion in 1989. The building was designed by Henry N. Cobb of the architectural firm Pei Cobb Freed & Partners and cost $350 million to build. It is one of the most recognizable buildings in Los Angeles, and often appears in establishing shots for the city in films and television programs.