Several months after the closing of the 1916 Panama-California International Exposition, the majority of the remaining exposition buildings were converted into a temporary Naval Training Camp, due to the United States' involvement in the World War. The buildings were used as barracks and schools for thousands of new recruits, as well as offices for Navy personnel. By the early 1920's the structures were showing their age, due to both the elements and hard use by the Navy for several years; and monies were allotted by the City of San Diego to make necessary repairs. In 1921 the former Southern California Counties Building was converted into San Diego's first Civic Auditorium at great expense. However, the building was completely destroyed by fire on the evening of November 25th, 1925, just prior to the annual Fireman's Ball; and the Natural History Museum was constructed on the site in 1932. The exposition's Sacramento Valley Counties / United States Government Building was replaced by the permanent reinforced-concrete Fine Arts Gallery in 1926, with funds donated by Mr. and Mrs. Appleton Bridges. By Spring of 1933 many of the aging wood-framed "temporary" exposition buildings were in deplorable condition. Sagging foundations, termite and moisture damage, cracked and falling plaster, broken ornamentation, and leaking roofs plagued the structures, which were subsequently condemned by city inspectors. The citizenry of San Diego were appalled that the beloved buildings were soon to be demolished, and a massive public outcry convinced the city to attempt to save the structures until permanent replacements could be funded. Local architect Richard Requa was hired to prepare an independent estimate for repairs, after the city's repair estimates were found to be exorbitant. Mr. Requa proved that the buildings could be repaired for much less than what the city estimated, and extensive renovation work soon began. Within several months the exposition buildings once again looked new, with the addition of concrete footings and foundations, replacement of damaged wood, repaired plaster and ornamentation, new roofing, and waterproof painting of exteriors. Only the former San Joaquin Valley Counties Building, and the Kern and Tulare Counties Building, had been found to be beyond repair and were demolished. In 1934 an idea was conceived to stage a second exposition, taking advantage of the newly renovated 1915 structures. San Diego's economy was at a standstill, due to the Great Depression, and an exposition was seen as a way to both create jobs and stimulate spending. The second season of Chicago's Century of Progress Exposition was coming to a close, and exhibits could be easily transferred to San Diego at minimal expense. The public was appealed to, fundraising soon began, and by late 1934, planning of the California-Pacific International Exposition was underway; with an opening date set for May 29th, 1935. Since the existing exposition structures would not accommodate all the displays intended, an additional section was planned south-west of the Spreckels Organ Pavilion, and named the Palisades. New exposition structures in this area were designed in an architectural progression from ancient to modern, beginning with the simple Pueblo-styled Palace of Education, Hollywood Motion Picture Hall of Fame, and Palisades Cafe; contrasting with the Aztec and Mayan-styled Palace of Travel, Transportation and Water, Federal Building, and Standard Oil Tower to the Sun; continuing with the merging of ancient and modern styles in the Palace of Electricity and Varied Industries, and the California State Building; and culminating with the ultra-modern Ford Motor Company exhibit building. Smaller structures of simple Spanish design were introduced in the area west of the Organ Pavilion; such as the Christian Science Monitor Building, and a group of fifteen international cottages known as the House of Pacific Relations. El Prado was re-named Avenida de Palacios, and the existing 1915 buildings were enhanced with colorful awnings and banners. The Plaza de Panama became the Plaza del Pacifico; featuring a central tile-roofed structure, with a broad archway spanning the Avenida de Palacios, and flanked by two large reflecting pools. North-east of the Avenida de Palacios was the amusement zone, known as the "Zocalo"; which also extended south into Spanish Canyon, re-named "Gold Gulch", and contained a simulated old-west mining town. The high-point of the exposition was the extensive use of colored flood-lighting, which illuminated buildings and landscaping in a myriad of hues during the evening hours.