One World Trade Center in New York City has been the tallest building in the United States since it was completed in 2013. Its height makes it the second-tallest free-standing building in the country after The Burj Khalifa in Dubai. The Chrysler Building, currently under renovation to become a luxury hotel, was once the tallest building in the world. When it was built in 1930, it was considered revolutionary because it used many materials not previously thought suitable for construction including aluminum, glass, and chrome. It remains one of the most famous architectural works of the Art Deco period. When it was first built, many people doubted that such a thin shell would be strong enough to support its weight. The Chrysler Building withstood several major earthquakes over the years without any apparent damage. World Trade Center No. 2 is the Sears Tower – now known as the Willis Tower (after its former owner) – which is located in Chicago. If it were standing today, it would be the second-tallest building in the world after One World Trade Center. However, it was demolished on March 14, 2002 after it was found to have numerous structural problems due to its age (it was constructed in 1973).