The Empire State Building is a 102-story Art Deco skyscraper in New York, NY. Its name is derived from the nickname for the state of New York. It stood as the world's tallest building for more than forty years, from its completion in 1931 until the construction of the World Trade Center North Tower in 1972, and is now once again the tallest building in New York after the destruction of the World Trade Center in the September 11, 2001 attacks. The Empire State Building has been named by the American Society of Civil Engineers as one of the Seven Wonders of the Modern World. The building and its street floor interior are designated landmarks of the New York City Landmarks Preservation Commission, and confirmed by the New York City Board of Estimate. The Empire State Building rises to 1,250 feet (381 m) at the 102nd floor, and its full structural height (including broadcast antenna) reaches 1,453 feet and 8 9/16th inches (443 m). The building has 85 stories of commercial and office space (2,158,000 square feet / 200,465 square meter) and an indoor and outdoor observation deck on the 86th floor. The remaining 16 stories represent the spire, which is capped by a 102nd floor observatory, and atop the spire is an antenna topped off with a lightning rod. The Empire State Building is the first building to have more than 100 floors. The building weighs approximately 370,000 tons (330,000 metric tonnes). It has 6,500 windows, 73 elevators and there are 1,860 steps from street level to the 102nd floor. It has a total floor area of 2,768,591 square feet (approximately 254,000 square metres).