Notes:
Notes:
"Significance This building was constructed in 1961-62 as the Washington State Coliseum, which would house the World of Century 21 during the Seattle World's Fair Century 21 Exposition. Financed by the State of Washington and built at a cost of $4,500,000, the Coliseum was located at the center of the International Plaza and ringed by the International Commerce and Industry Buildings, part of the World of Commerce and Industry. The fair's primary architect, Paul Thiry, designed both the Coliseum and the buildings surrounding it, although the other buildings were constructed with funding from King County. From the very beginning, there was the intention to convert the Coliseum to an 18,500-seat sports and convention facility at the conclusion of the fair. The City of Seattle would purchase the facility, which would become one of the key structures of the new Seattle civic center. The future sports facility's need for unobstructed space greatly influenced the innovative design of the structure. Since its completion in 1928, the city's Civic Auditorium complex of three buildings and a sports stadium had been located in the mostly residential neighborhood. The complex was diagonally adjacent to Mercer Playground, which was developed in 1910 and named for Seattle pioneer Thomas Mercer, who homesteaded in the vicinity. Covering an entire city block, Mercer Playground served both the surrounding neighborhood and the 1902 Warren Avenue School located across the street to the west. By the mid-1950s, the city began to conceive a new plan for the Civic Auditorium complex, which would create new cultural and sports facilities. In November 1956, the City held a special municipal election to approve a $7,500,000 bond issue to fund the acquisition of a site for a Civic Center development, the construction of a concert and convention hall and multi-purpose auditorium, and the modernization and remodeling of the Civic Auditorium. The City planned these improvements with the idea that the new Civic Center could also be used for the proposed Seattle World's Fair along with nearby property acquired by the State. As plans developed, it was determined that the State of Washington would build the structure that would become the new civic center's sports facility. Part of the land designated for this structure had been the site of the Warren Avenue School, acquired from the Seattle School District through the condemnation proceedings. Unlike many of the fairÃÂs permanent buildings, the design of this structure had been finalized relatively early on in the planning process. At the time of its construction, it was considered one of the largest clear-span structures in the world and was believed to be the first clear-span, tri-level exhibition pavilion. Covering almost four acres and enclosing some 130,000 square feet of unobstructed space, the building featured an aluminum roof, the only one of its kind in existence. The roof swept 110 feet into the air at the apex, and was supported by steel compression trusses rising from four massive tripedal concrete abutments. The hyperbolic parabolic shape enabled there to be no interior roof supports. Architect Paul Thiry believed that the unique roof structure would have wide applications where large areas must be covered, possibly as much as a square-mile area. The building quickly became a prominent feature on the local landscape, especially with its silvery roof, accented by the red truss covers and topped by a gold-anodized monitor. Born in Alaska in 1904, Paul Thiry received his education in architecture at the University of Washington, graduating in 1928. After a brief stint working with the architect Butler Sturtevant, Thiry began his own practice in 1929 and usually worked alone or with only one or two people at the most. Much of ThiryÃÂs early work consisted of apartment buildings and small private residences using conventional Norman and Colonial Revival forms. By 1934, the Depression had caused a major reduction in his workload. Thiry saw this as an opportunity to travel, taking a yearlong trip around the world. Upon his return, he introduced the Pacific Northwest to the architecture of the European Modernists. Among the many accomplishments of his long career, Thiry would later help to develop the regional variant, Northwest Contemporary Modernism, a style that combined elements from the International Style, traditional architecture of Japan, and local vernacular traditions and materials. During the fair, the interior of the structure was filled with exhibits and attractions, which would provide a view into the world of the future, the World of Century 21. Washington's theme exhibit, entitled 'Century 21 - The Threshold and the Threat,' was the centerpiece. Rising in the center of the Coliseum was an overhead structure, measuring 200 feet across and 60 feet high, of some 3,500 interlocking multicolored aluminum cubes, each four feet square and bathed in light. One hundred visitors at a time would ascend 28 feet to the structure of cubes within a transparent globe-shaped elevator, known as the Bubbleator, for a 21-minute tour of the future. Some of the cubes served as three-dimensional projection screens and some contained backlighted models while others housed complex sound and lighting equipment. The 'World of Tomorrow' would include a look at the city of tomorrow, the home of the future, and transportation, industry, food production, education, communications and recreation in the 21st century. It was thought that the threshold of the future was threatened by man's inhumanity to man. The remaining portion of the structure around the perimeter contained the General Motors Corporation Exhibit, the Pan American Airways Exhibit, a Washington Tourist Information Center, the Government of France Exhibit, a Cancer Research Exhibit, and the Radio Corporation of America Exhibit. After the conclusion of the fair in October 1962, the Coliseum was sold to the City of Seattle and converted into the planned sports and exhibition facility. The exhibits were removed, and the Bubbleator was relocated from the Coliseum to the Food Circus. For many years afterwards, it ferried visitors between the basement, main floor and mezzanine before its removal in a 1980 renovation project. Since 1967, the Coliseum's primary tenant has been the Seattle SuperSonics NBA basketball team, except for a seven-year hiatus between 1979 and 1985 when they played in the Kingdome. The Coliseum has also hosted rock concerts, the circus, and many other events over the years. In the mid-1990s, the Coliseum was substantially reconstructed and renamed KeyArena when it reopened in late October of 1995. Despite the alterations, this building is significant for its design as the work of a major local architect and for its associations with the Seattle World's Fair Century 21 Exposition and the development of the Seattle Center."