Wikipedia, written by someone interested in pepping up the usual tone, says:

The Pioneer Hotel, designed by Tucson architect Roy Place, was one of Tucson's first high-rise buildings. Opened in 1929, the Spanish Revival hotel became the social center of the downtown business district. The property catered to the social elite.

In the mid-20th century Harold and Margaret Steinfeld, owners of a large downtown department store, lived in the penthouse. A disastrous fire severely damaged the building in December 1970, and among the 29 victims were the Steinfelds. The building has been converted from a hotel to an office building.

Though it adds a rich layer of history to the business district of downtown Tucson, the Pioneer Hotel has not been listed in the National Register of Historic Places because of "irreversible integrity changes" made in the late 1970s and early 1980s.

You could say that about many downtowns. It was modernized after the fire, and it wasn't pretty.