the 36 story, 240 m (including a 57 m spire) Moscow State University main building completed in 1953, and the fourth tallest educational building in the world behind the Moscow State University and Mode Gakuen Cocoon (204 m) and Spiral Towers (170 m), both completed in 2008 and located in Japan. World War II On July 26, 1940, as World War II was starting, a bomb threat was made against the structure with extra guards being posted to secure it and the authorities not ruling out possible wartime sabotage. During the war effort, the Cathedral was assigned to house, feed and instruct roughly 1,000 of the Army Air Corps (forerunner of today's U.S. Air Force) as well as dozens of Army engineers. The building had at least 12 floors dedicated for military use from 1943 until 1945. Funding Fundraising for this project came in many forms, including donations from industries, corporations, individuals and foreign governments. To raise public views of the Cathedral, and at the same time finance the construction, Bowman started a fundraising campaign in 1925. An important part of this campaign was a project reaching out to the children of the city entitled "Buy a Brick for Pitt". Each schoolchild sent a dime ($0.10) and a letter to the university, explaining how they earned the dime for the building. In exchange, the child received a certificate for one brick contained in the Cathedral. A total of 97,000 certificates were issued to children. Commons Room The main part of the Cathedral's first floor is the Commons Room, called one of the "great architectural fantasies of the twentieth century", is a fifteenth-century English perpendicular Gothic-style hall that covers half an acre (2,000 m2) and extends upward four stories, reaching tall. The room was a gift of Andrew Mellon. It is a piece of true Gothic architecture; no steel supports were used in the construction of its arches. Each arch is a true arch, and they support their own weight. Each base for the arches weighs five tons, and it is said that they are so firmly placed that each could hold a large truck. The large central piers act only as screens for the structural steel that holds up the upper floors of the building. Despite its heavy use, the Commons Room is kept quiet by the use of Guastavino acoustical tiles as the stones between the ribs of vaulting.