of another renovation, Sheraton sold the building to Herbert R. Weissberg and it became the Detroit-Cadillac Hotel. Soon after, Weissberg defaulted on a loan, and the Bank of the Commonwealth acquired the hotel's mortgage. They partnered with Minneapolis-based Radisson Hotels to manage the hotel and oversee renovations, as Radisson had just successfully done at Kansas City's Muehlebach Hotel. The remodeling work cost $6 million, and the hotel reopened in June 1978 as the Radisson Cadillac Hotel. Though it had been considered the city's top hotel for many years, in late 1979, the owners announced that the hotel would close due to declining occupancy. The City of Detroit, scheduled to host the 1980 Republican National Convention, did not want to face the prospect of losing more downtown hotel space, so the city entered into a partnership through the Detroit Economic Growth Corporation with the owners to keep the hotel open. The hotel ceased to be managed by Radisson in 1980 and became the Book Cadillac Hotel once again. By that point, multiple guestroom floors of the aging hotel had been entirely closed off and mothballed, and only 768 of its 947 rooms were considered "saleable." In 1983, it was decided that the only way to bring the financially ailing hotel back to profitability was to convert it into a mixed-use property. The hotel's nearly 1000 rooms were deemed too numerous to fill and were far too small by modern standards. The plan would turn the building into the Book-Cadillac Plaza, containing a smaller 550-room hotel on 12 floors, and 11 floors of redeveloped office space. The hotel closed its doors in October 1984 for the renovation. However, those plans were quickly dashed, as proposed construction costs soared, and Detroit's economic situation continued to deteriorate. For the next two years, developers came and went, but with no one able to take on the increasingly complex renovation, the building's contents were finally liquidated in 1986. After the sale, the hotel's retail tenants, who had planned to stay through the renovation, moved out and the building was shuttered. It would remain in that state for the next 20 years. Time passed and the unmaintained property decayed, a it fell victim to the elements, vandalism, and urban scavengers. In July 2003, after years of legal battles to fully acquire the building and find a developer, the city of Detroit announced a $150 million renovation deal