Plans are moving forward to redevelop property at 515 Walnut St., the site of the now vacant indoor mall, food court and office building called Kaleidoscope at the Hub.

515 Walnut LLC, managed by Joseph Teeling, has proposed the construction of a 33-story, mixed-use tower on the site. The high-rise would include 390 apartment units and street-level commercial space. Construction of the project, estimated to cost $140 million, is expected to begin yet this year.

However, before construction on the tower can begin, the site’s structure must be demolished. The three-story building, constructed in the mid-1980s, includes connections to the 4.2-mile downtown skywalk system operated by the city of Des Moines. In addition, a portion of the skywalk goes through the building. Before the building can be demolished, approval was needed from the Des Moines City Council to allow the building to be razed.

The council this week approved moving forward with the building’s demolition, which could occur yet in June, according to information provided to the council.